Abstract: A mathematical model of a slow-speed, long-stroke piston compressor with lumped parameters of the work process is considered. The influence of the structural and regime parameters on the efficiency of the work process is estimated from the results of a computational analysis. A comparative estimate of existing techniques for the analysis of heat-exchange processes in the working cavity is conducted.

Abstract: The invention discloses a dielectric barrier discharge non-equilibrium plasma spark plug for an internal combustion engine, and belongs to the field of internal combustion engine combustion. An inner electrode of the spark plug is arranged at the center; an ionization cavity is formed in a space between the lower part of a first insulating layer and the lower part of the inner electrode; a bulge is arranged on the surface of the inner electrode positioned in the ionization cavity. A small amount of combustible gas mixture is pressed into the ionization cavity during compression stroke, and the combustible gas mixture is ionized to form non-equilibrium plasma. The formed non-equilibrium plasma has high chemical activity, rushes out from the ionization cavity, enters combustion chamber space, stimulates gas mixture positioned in the combustion chamber space through the high activity of high-energy electron, and begins chain reaction. The non-equilibrium plasma is widely distributed in the combustion chamber space, so that space multi-point ignition is realized. The spark plug can improve the ignition energy of a spark ignited engine, improves the combustion stability and the emission performance of a lean-burn engine, and expands the lean burn limit of the engine, thereby improving the economical efficiency of the engine.

Abstract: A piston compound internal combustion engine is disclosed with an expander piston deactivation feature. A piston internal combustion engine is compounded with a secondary expander piston, where the expander piston extracts energy from the exhaust gases being expelled from the primary power pistons. The secondary expander piston can be deactivated and immobilized, or its stroke can be reduced, under low load conditions in order to reduce parasitic losses and over-expansion. Two mechanizations are disclosed for the secondary expander piston's coupling with the power pistons and crankshaft. Control strategies for activation and deactivation of the secondary expander piston are also disclosed. In addition, six-cylinder engine configurations are defined by replicating groups of two power pistons and one expander piston.

Abstract: The utility model belongs to the mechanical structure field especially relates to a straight reciprocating motion mechanism, aim at solving linear motion stroke ram travel less, two crank link mechanism that current single crank link mechanism produced uncertain with transmission precision poor and both all have the technical problem that dead center position inertia strikes. The opposite ends difference pin joint of connecting rod makes the eccentric gear of first eccentric gear and second keep the centre -to -centre spacing of invariant on first eccentric gear and eccentric both centres of a circle of gear of second. Let first eccentric gear steady rotation, first eccentric gear and the eccentric gear meshing transmission of second, the slider output straight reciprocating motion of pin joint in the eccentric gear off -centre of second. Two eccentric gears mesh mutually can gain big stroke linear motion effect with the combination of connecting rod. Two eccentric gears mesh mutually, can not have dead center position, avoid inertia to strike, smooth operation, and reliable operation, ram travel confirm that transmission precision is high.

Abstract: PROBLEM TO BE SOLVED: To provide a brake control system capable of acquiring a high fluid pressure at later period of a depression operation even in the case where a booster ratio is made higher for a later period than for an earlier period of the brake depression operation.SOLUTION: A brake control system comprises: a master cylinder 4 linking to a brake pedal for actuating to establish a liquid pressure; a rod 3 connected rotatably to a primary piston; and a booster deice 2 for connecting the brake pedal and the rod for amplifying and transmitting a tread force to the rod. The primary piston is provided in a first region to have an area (or a first pressure receiving area) of a first piston 41Pa when the pedal stroke is less than a predetermined value SR*, and in a second region to have an area (or a second pressure receiving area larger than the first pressure receiving area) obtained by adding the area of the first piston and the area of the second piston 41Pb when the pedal stroke is equal to or more than the predetermined value. The booster device is a mechanical link mechanism for adjusting a piston stroke against the pedal stroke.

Abstract: The invention relates to an actuating system for a vehicle brake, with an actuating arrangement, in particular a brake pedal, at least one (first) piston-cylinder unit, which is connected via a hydraulic line to the vehicle brake (braking circuit) in order to supply the braking circuit with pressure medium and apply pressure to the vehicle brake, and with a drive for the piston-cylinder unit. According to the invention, pressure medium can be fed to the braking circuit in controlled manner in both piston movement directions, in particular the advance stroke and the return stroke, by means of at least one, in particular stepped, piston (10) of the piston-cylinder unit (10, 10a, 10b).

Abstract: The invention discloses a reciprocating seal experiment table for measuring a friction feature of a single seal ring. The experiment table is composed of an experiment cylinder, a high-pressure simulation system, a high-speed drive oil cylinder and a hydraulic system of the experiment table, wherein the high-pressure simulation system and the high-speed drive oil cylinder are connected with the experiment cylinder. A cylinder body of the experiment oil cylinder is installed on a work table through a linear guide rail, the high-speed drive oil cylinder drives the experiment cylinder to reciprocate through a connecting flange, a piston rod of the experiment cylinder is fixed and is divided into two halves, the two halves are connected through a pull pressure sensor and are fixed to the work table. A bushing, used for installation of the seal ring, of the experiment cylinder can be replaced, and therefore seal rings with different pre-compression amounts and different section shapes can be measured conveniently. A high-pressure oil supply system provides a high-pressure working simulation environment inside the experiment cylinder, and the experiment table can adjust the reciprocating speed, strokes and in-cylinder pressure of the drive oil cylinder. The experiment table can measurement the friction feature of the inner stroke and the outer stroke of the single seal ring, the leakage amount and the medium temperature after reciprocating for several times .

Abstract: The utility model aims to disclose an automatic reciprocating scraping type bamboo skin removing device which can improve the work efficiency of bamboo skin removal and reduce labor intensity of workers on the premise of keeping the toughness of bamboo to the maximum extent. The automatic reciprocating scraping type bamboo skin removing device comprises a rack, a knife rest, a knife rest reciprocating drive mechanism and a knife rest rotating drive mechanism. The knife rest rotating drive mechanism is formed by a base, a round support and a drive motor. The base is connected with the knife rest reciprocating drive mechanism. The knife rest comprises at least one blade group. Each blade group comprises two opposite blades. The blades are connected with the round support through an elastic pressing mechanism and accordingly the two blades in the same blade group can clamp tight bamboo penetrating through between the two blades. A limit mechanism used for restricting the position of the bamboo is further arranged on the rack. A travel switch is arranged on the rack at the end of the reciprocating stroke of the base and is connected with the drive motor to control the drive motor to work.

Abstract: Laser-induced incandescence (LII) was performed at 3 kHz in an optically accessible cylinder of a fired diesel engine using a commercially available diode-pumped solid-state laser and an intensified CMOS camera. The resulting images, acquired every 3° of crank angle, enabled the spatiotemporal tracking of soot structures during the expansion/exhaust stroke of the engine cycle. The image sequences demonstrate that soot tends to form in thin sheets that propagate and interact with the in-cylinder flow. These sheets tend to align parallel to the central axis of the cylinder and are frequently wrapped into conical spirals by aerodynamic swirl. Most of the soot is observed well away from the cylinder walls. Quantitative soot measurements were beyond the scope of this study but the results demonstrate the practical utility of using kHz-rate LII to acquire ensemble-averaged statistical data with high crank angle resolution over a complete engine cycle. Based on semi-quantitative measures of soot distribution, it was possible to identify soot dynamics related to incomplete charge exchange. This study shows that long-duration, multi-kHz acquisition rate LII measurements are viable in a fired diesel engine with currently available laser and camera technology, albeit only in the expansion and exhaust phase of the cycle at present. Furthermore, such measurements yield useful insight into soot dynamics and therefore constitute an important new tool for the development and optimization of diesel engine technology.

Abstract: A hydraulic pumping assembly provides reciprocating motion to a sucker rod string coupled to a downhole pump. The pumping assembly includes a hydraulic cylinder, a cylinder rod, a telescoping cylinder sleeve for increasing the effective stroke length, and a cylinder base positioned below the hydraulic cylinder. The hydraulic cylinder includes a cylinder barrel, a cylinder head, a piston, and a port configured to direct hydraulic fluid to and from the cylinder barrel. The piston is coupled to the cylinder rod at an upper end of the rod. The cylinder rod slides within the cylinder sleeve, which passes slideably through the cylinder head. The cylinder sleeve moves between an extended position and a retracted position as the piston reciprocates within the cylinder barrel. The cylinder base accommodates the cylinder rod and the telescoping cylinder sleeve in a collapsed position.

Abstract: The structure of in-cylinder flow field makes significant impacts on the processes of spray injection, air-fuel interactions, and flame development in internal combustion engines. In this study, the implementation of time-resolved Particle Image Velocimetry (PIV) in an optical engine is presented. Images at different crank angles have been taken using a high-speed double-pulsed laser and a high-speed camera with seeding particles mixed with the intake air. This study is focused on measuring the flow fields along the swirl plane at 30 mm below the injector tip under different intake air swirl ratios. A simple algorithm is presented to identify the vortex structure and to track the location and motion of vortex center at different crank angles. Proper Orthogonal Decomposition (POD) has been used to extract the ensemble and variation information of the vortex structure. Experimental results reveal that strong cycle-to-cycle variations exist in almost all test conditions. The vortex center is difficult to identify since multiple, but small scale, vortices exist during the early stage of the intake stroke. However, during the compression stroke when only one vortex center exists in most cycles, the motion of vortex center is found to be quite similar at different intake swirl ratios and engine speeds. This is due to the dominant driving force exerted by the piston’s upward motion on the in-cylinder air.© 2014 ASME

Abstract: An internal combustion engine system includes: an in-cylinder pressure sensor; a crank angle sensor; and a seal portion that seals a space between an outer face of a housing and a wall surface of a cylinder head. A slope that is a ratio of the amount of decrease in a heat release amount relative to the amount of increase in a crank angle is calculated in a period during an expansion stroke from a combustion end point until an opening timing of an exhaust valve. The existence or nonexistence of an abnormality in the sealing function of the seal portion is determined based on whether or not a ratio of the amount of decrease in the slope to the amount of increase in an engine speed is greater than a threshold value.

Abstract: Various embodiments of the present disclosure are directed towards free-piston combustion engines. As described herein, a driver section may be provided in a free-piston combustion engine for storing energy during an expansion stroke. The driver section may be configured to store sufficient energy to perform the subsequent stroke. In some embodiments, the driver section may be configured to store sufficient energy so as to enable the engine to operate continuously across engine cycles without electrical energy input. A linear electromagnetic machine may be provided in a free-piston combustion engine for converting the kinetic energy of a piston assembly into electrical energy.

Abstract: The invention relates to a lightning stroke fault determination method based on a waveform difference degree and a lightning stroke fault sample database. According to the method, when a fault occurs at a power transmission line, a travelling-wave fault range finding apparatus records a fault waveform; calculation is carried out by using a cubic b-spline wavelet to obtain an initial traveling wave arrival time of the fault; data 5ms after the initial traveling wave arrival time are selected to carry out normalization processing; the fault waveform after normalization processing is compared with all waveforms in the lightning stroke fault sample database and waveform difference degrees are calculated; and if a minimum value of difference degrees of the fault waveform and all waveforms in the lightning stroke fault sample database is less than a set threshold value, the fault type is determined to be a lightning stroke fault type; and otherwise, the fault type is determined to a non-lightning stroke fault type. According to the invention, compared with the existing lightning stroke fault identification method, the provided determination method has the following beneficial effects: confirmation of fault points by field line patrol workers is not required; the accuracy is high; and the method is simple and effective.

Abstract: A control system for an internal combustion engine has an intake valve, an exhaust valve, and an exhaust purifying catalyst that purifies exhaust gas after combustion of a fuel. During a fuel cut in which no fuel is supplied, a closing timing of the intake valve is controlled to a delayed angle side more than at a timing when the fuel is supplied and to a delayed angle side more than at a timing at a bottom dead center of an intake stroke, and an opening timing of the exhaust valve is controlled to an advanced angle side more than at the timing when the fuel is supplied and to an advanced angle side more than at the timing at the bottom dead center of an expansion stroke.

Abstract: A mixture-charged gas engine includes at least one cylinder. A combustion chamber delimited by a cylinder head, a cylinder wall, and a piston, which can be moved in the cylinder, is arranged in the at least one cylinder, and the combustion chamber is divided into a main combustion chamber and at least one pre-chamber fluidically connected to the main combustion chamber via at least one firing channel. An air-/combustion gas mixture can be supplied to the main combustion chamber via an inlet valve during an intake stroke of the piston. The mixture-charged gas engine is characterized in that a separate combustion gas supply is provided for the at least one pre-chamber.

Abstract: The invention discloses a driving device for a large-sized reciprocating motion machine tool. According to the driving device, two same hydraulic cylinders are fixed together in parallel in the opposite directions, a piston rod of each hydraulic cylinder is provided with a pulley, one end of a sliding workbench of the machine tool is fixedly connected with one end of one steel wire rope, and after the steel wire rope passes through the pulley on the edge where the steel wire rope is located, the other end of the steel wire rope is fixedly connected with a machine tool body; the other steel wire rope is fixed at the other end of the sliding workbench of the machine tool, and after the steel wire rope passes through the pulley on the edge where the steel wire rope is located, the other end of the steel wire rope is fixedly connected with the machine tool body. According to the driving device, in the strokes of the piston rods of the hydraulic cylinders, the sliding workbench can obtain the doubled stroke distance of the piston rods, the purpose of lowering costs can be achieved, in particular, the advantage of being easy to manufacture is achieved, and the sliding workbench with a large stroke of the machine tool can be driven.

Abstract: The invention provides a piston type air-powered engine system capable of providing power for a vehicle, an engineering machine, a power generation device and the like and belongs to the field of power machinery. The piston type air-powered engine system utilizes gas stored in a high-pressure gas tank, and the gas is buffered and then is fed into an air cylinder through a gas distribution mechanism to push a piston to do work. Compared with a piston type internal combustion engine, a piston type air-powered engine is stable in working doing process and small in noise. The piston type air-powered engine is a two-stroke engine, namely adopts an intake work-doing stroke and an exhaust stroke, the operation process of the piston type air-powered engine is mainly a compressed gas expansion work-doing process and is a physical change process, and no exhaust pollution exists.

Abstract: An air displacement pipette includes a segmented, stepped piston configured to displace additional air at a higher velocity during a blowout stroke, thereby enabling improved dispensing accuracy by more completely dislodging adhering liquid from a pipette tip following the preceding dispensing stroke.

Abstract: The invention discloses a pole-climbing robot An upper elastic claw device is elastically abutted against two sides of a driven cam; a lower part elastic claw device is elastically abutted against a curve external edge of a driving cam; the upper part elastic claw device and the lower part elastic claw device are controlled to alternatively conduct clamping actions via changes of the sizes of the external edge of the driving and driven wheels; a displacement reference point is provided for the other elastic claw device by the alternated elastic claw device; a crank drives the upper and lower elastic claw devices to alternatively move upward to achieve stroke changes; further the driving cam is a parallel-connected cam formed by a first driving cam and a second driving cam, so a clamping period of the lower part elastic claw device is the same as a pushing period of a second crankshaft; the upper elastic claw device can be ensured to finish upward displacement; and with cooperation among the driving cam, the driven cam and the stroke changes, actions of clamping, expanding, lifting and pushing of the pole-climbing robot can be finished through only one power mechanism

Abstract: The invention provides an automatic stop/restart control system for an internal combustion engine and a variable valve actuating apparatus. After fuel injection stops and a restart request is generated to allow fuel to be supplied again, combustion torque of combustion gas obtained by combustion of fuel is effectively utilized, and therefore the proportion of starting without a starter is increased. After fuel injection stops, the valve opening time of an exhaust valve is made to be delayed in a vicinity of a bottom dead center on an expansion stroke during a decrease in the rotating speed of the internal combustion engine, and combustion torque of the combustion gas from fuel generated by fuel injection during restart is effectively utilized. Therefore, after fuel injection stops and a restart request is generated for restart, the combustion torque obtained by combustion of fuel is effectively utilized. In this way, the lower-limit rotating speed of starting without a starter can be reduced and the proportion of starting without a starter is increased.

Abstract: A color paste pump capable of both massive injection and micro injection, the pump comprising: a large reciprocating displacement pump (1, 2, 5), the large reciprocating displacement pump (1, 2, 5) comprising a large reciprocating piece (2, 2a, 2b), a large pump body (1) and a large pump port (5); a small reciprocating piece (3) fixed to the large reciprocating piece (2, 2a, 2b) is disposed within the large pump body (1); a small pump body (4) is disposed on a large pump body base (102, 110); the small pump body (4) is provided with a small pump port (6); the small reciprocating piece (3), the small pump body (4) and the small pump port (6) constitute a small reciprocating displacement pump (3, 4, 6). The color paste pump is capable of both massive injection and micro injection of color paste, thus ensuring injection precision of color paste injection volume, in particular micro injection volume. The pump has high precision and a simple structure, and moreover, has good anti-leak performance, high utilization in the length direction of the reciprocating cylinder body, and small elastic deformation of a pump frame, thereby improving reciprocating pump stroke precision.

Abstract: A gas operating system for engaging the automatic or semi-automatic action of small arms. The system has a short, displaceable cylinder with a gas block ring secured thereto, a short, fixed piston attached coaxially to a gun barrel, and a single locking nut, advantageously in the form of a threaded flash suppressor. The piston includes gas block rings at its rearward exterior surfaces. The cylinder has a short stroke between radial forward and rear stops fixed on the barrel, which short stroke may be finely adjusted by threaded axial displacement of the rear stop. Pressurized combustion gas from fired ammunition fills a gas chamber formed by the interiors of the piston and cylinder, the gas entering through radial ports in the barrel. The system may be machined and assembled/disassembled with ease and may be readily adapted for employment in any small arms. The system may be fine tuned for usage with a wide spectrum of ammunition.

Abstract: A 2-stroke combustion cycle has higher power output densities compared to a 4-stroke cycle counterpart. The modern down-sized 4-stroke engine design can greatly benefit from this attribute of the 2-stroke cycle. By using appropriate variable valvetrain, boosting, and direct fuel injection systems, both cycles can be feasibly implemented on the same engine platform. In this research study, two valve strategies for achieving a two-stroke cycle in a four-stroke engine have been studied. The first strategy is based on balanced compression and expansion strokes, while the gas exchange is done through two different strokes. The second approach is a novel 2-stroke combustion strategy - here referred to as 2-stroke Miller - which maintains the expansion as achieved in a 4-stroke cycle but suppresses the gas exchange into the compression stroke. The first 2-stroke cycle generated a torque increment of 63% at 1000 rpm on a supercharged 4-stroke engine without increasing the maximum cylinder pressures. The second 2-stroke strategy - which uses the Miller cycle concept - generated a torque increase of 51.5% at 1000 rpm and higher thermal efficiencies than the first valve strategy. The 2-stroke Miller cycle has been proposed as a means of transitioning from 4 to 2-stroke with progressive torque delivery and without requiring a throttled intake. The 2-stroke cycle appears to be a potential solution to overcome some of the difficulties faced by downsized gasoline engines during high load operations. In particular this cycle will be beneficial in a condition where the engine is already operating at peak cylinder pressures and additional torque output is not easily achievable.