Variable-volume piston assembly and engine

Abstract

The invention relates to the technical field of engine parts, and provides a variable-volume piston assembly and an engine, the variable-volume piston assembly comprises a piston cylinder, a piston rod and a variable-volume flexible piston, one end of the flexible piston is open, the other end of the flexible piston is closed, the open end is fixedly connected with the piston cylinder, and the piston cylinder is provided with an air inlet and an air outlet which are communicated with the open end; the piston rod is connected with the closed end of the flexible piston, the valve body is fixedly connected with the piston cylinder, and the air inlet and the air outlet are formed in the valve body; the valve element is arranged in the valve body in a sliding mode and used for closing the air inlet or the air outlet, and a boss is arranged at the closed end of the flexible piston and used for pushing the valve element to move to close the air outlet; one end of the valve rod is connected with the boss, and a clamping head is arranged on the valve rod and used for pushing the valve element to move to close the air inlet. Dynamic switching of air inlet and air outlet is achieved through back-and-forth movement of the valve element, an independent valve does not need to be arranged, it is avoided that external energy is consumed to control opening and closing of the valve, and the energy-saving effect is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of engine components, and in particular to a variable volume piston assembly and an engine. Background Art

[0002] Energy conservation and emission reduction have always been the focus of attention in various industries such as energy, chemical industry, electricity, and construction in the new era. Among them, waste heat utilization technology has been studied and developed for many years, and many achievements have been made. From the temperature of waste heat, it can be roughly divided into high-temperature waste heat (>500°C), medium-temperature waste heat (500-200°C), and low-temperature waste heat (<200°C). At present, high-temperature waste heat can be directly used for heating, or equipped with steam waste heat boilers, and then equipped with steam engines for power generation. The conversion and utilization of medium-temperature waste heat and low-temperature waste heat can be achieved through the Brayton cycle system and the organic Rankine cycle system. These systems all involve the expansion and compression of gases through expanders and compressors. Due to factors such as friction loss and leakage loss, the mechanical loss of traditional expanders is relatively large, which seriously affects the economic efficiency when converting and utilizing low-temperature waste heat with a temperature of less than 150°C.

[0003] For piston-type expanders and compressors, mechanical losses are mainly in the piston assembly parts. For this reason, the existing technologies (such as patent documents with publication numbers "CN106321280A", "CN106337757A", "CN107401463A", "CN116292496A", "CN117605650A", etc.) use variable-volume pistons to reduce friction losses and leakage losses, thereby achieving the purpose of reducing mechanical losses and providing the possibility for the conversion and utilization of low-temperature waste heat with a temperature less than 150°C. However, in the prior art, the air inlet and exhaust ports of the piston assembly need to use independent valves, and these valves need to be equipped with corresponding control mechanisms (such as cam mechanisms) to control their opening and closing (or switching), and the operation of these control mechanisms requires the consumption of external energy (such as electricity and gas), and the overall energy-saving effect needs to be improved. Summary of the invention

[0004] The object of the present invention is to provide a variable volume piston assembly and an engine to improve energy saving effect.

[0005] The present invention is achieved through the following technical solutions:

[0006] A variable volume piston assembly includes a piston cylinder, a piston rod and a flexible piston with variable volume, wherein one end of the flexible piston is open and the other end is closed, the open end is fixedly connected to the piston cylinder, the piston cylinder is provided with an air inlet and an exhaust port connected to the open end, the piston rod is connected to the closed end of the flexible piston, and further includes:

[0007] The valve body is fixedly connected to the piston cylinder, and the air inlet and the air outlet are arranged on the valve body;

[0008] A valve core is slidably disposed inside the valve body and is used to close the air inlet or the air outlet. A boss is provided at the closed end of the flexible piston so as to push the valve core to move to the closed air outlet when the flexible piston contracts to a limit state; and

[0009] One end of the valve stem is connected to the boss, and a clamp is provided on the valve stem to push the valve core to move to the closed air inlet when the flexible piston expands and stretches to the limit state.

[0010] Optionally, it also includes a lock core, a lock seat and an elastic locking component, the lock core is fixedly connected to one end of the valve core, two lock grooves are arranged in parallel on the lock core, the lock seat is fixedly arranged, and the elastic locking component is arranged on the lock seat. The elastic locking component is inserted into one of the lock grooves when the valve core closes the exhaust port, and is inserted into the other lock groove when the valve core closes the air inlet.

[0011] Optionally, at least one pair of elastic locking components are symmetrically arranged.

[0012] Optionally, the elastic locking component includes a spring and a steel ball, and when the locking groove is aligned with the steel ball, the steel ball is snapped into the locking groove under the elastic force of the spring.

[0013] Optionally, a guide seat is fixedly provided in the valve body, and the valve stem is slidably matched with the guide seat.

[0014] Optionally, a linear bearing is provided between the guide seat and the valve stem.

[0015] Optionally, the clamping head is located on a side of the guide seat away from the valve core, a bearing member is provided in the valve body, the bearing member is fixedly connected to the valve core or the clamping head, and the clamping head can pass through the guide seat to transmit the thrust of the clamping head to the valve core.

[0016] The present invention also provides an engine, comprising one or more variable volume piston assemblies as described in any one of the above.

[0017] The technical solution of the present invention has at least the following advantages and beneficial effects: in the present invention, when the flexible piston shrinks to the limit state, the provided boss can push the valve core to move to the closed exhaust port, and when the flexible piston expands and stretches to the limit state, the provided clamping head can push the valve core to move to the closed air inlet. In this way, the dynamic switching of intake and exhaust is achieved by utilizing the back and forth movement of the valve core, without the need to equip an independent valve, avoiding the consumption of external energy to control the opening and closing of the valve, thereby improving the energy-saving effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 A schematic diagram of the structure of a variable volume piston assembly provided by the present invention (the flexible piston is contracted and shortened to the limit state);

[0020] Figure 2 A schematic diagram of the structure of a variable volume piston assembly provided by the present invention (the flexible piston expands and stretches to the limit state);

[0021] Figure 3 It is a structural schematic diagram of the lock core, valve core and collision bearing member;

[0022] Icon: 1-piston cylinder, 2-piston rod, 3-flexible piston, 301-boss, 4-air inlet, 5-exhaust port, 6-valve body, 7-valve core, 701-notch, 8-valve stem, 9-lock core, 901-lock groove, 10-lock seat, 11-spring, 12-steel ball, 13-guide seat, 14-chuck, 15-impact part. DETAILED DESCRIPTION

[0023] Example 1

[0024] refer to Figure 1 and Figure 2 A variable volume piston assembly includes a piston cylinder 1, a piston rod 2 and a flexible piston 3 with a variable volume. It should be noted that the "flexibility" of the flexible piston 3 should not be understood as limiting the material itself to be a flexible material, but should be understood as the flexible piston 3 as a whole can expand and contract during the intake and exhaust process, and is flexible as a whole. The material can be metal or non-metal. Preferably, it is a non-metal material, such as rubber, nylon, ethylene and the like. When it is metal, it can be, for example, a metal bellows.

[0025] One end of the flexible piston 3 is open and the other end is closed. The open end is fixedly connected to the piston cylinder 1 (for example, connected by bolts or screws). The piston cylinder 1 is provided with an air inlet 4 and an exhaust port 5 connected to the open end, that is, the flexible piston 3 constitutes a cavity for enclosing gas. When air is taken in, the flexible piston 3 expands, and the closed end moves away from the open end (the whole is extended). Similarly, when air is exhausted, the flexible piston 3 contracts, and the closed end moves closer to the open end (the whole is shortened). The piston rod 2 is connected to the closed end of the flexible piston 3. The piston rod 2 moves back and forth following the expansion and contraction of the flexible piston 3. In actual applications, the piston rod 2 is passed through the piston cylinder 1, and a linear bearing is provided to provide guidance for the piston rod 2 and reduce friction. It should be noted that since the piston cylinder 1 does not act as a sealed cavity in the present invention, the piston cylinder 1 can be a closed cylinder structure or an open structure.

[0026] On the basis of the above, the variable volume piston assembly further includes a valve body 6 , a valve core 7 and a valve stem 8 .

[0027] The valve body 6 is fixedly connected to the piston cylinder 1 (for example, by welding), and the air inlet 4 and the air outlet 5 are arranged on the valve body 6. In practical applications, in order to facilitate installation, the valve body 6 can be designed to be split, and the valve body 6 can be split into a front valve body 6 ( Figure 1 and Figure 2 The part close to the piston cylinder 1) and the rear valve body 6 are connected by screws or bolts.

[0028] The valve core 7 is slidably disposed inside the valve body 6 and is used to close the air inlet 4 or the exhaust port 5. On this basis, it should be understood that the valve core 7 can slide freely along the extension direction of the flexible piston 3. When sliding to the exhaust port 5, the exhaust port 5 is blocked, and the air inlet 4 is connected to the inside of the flexible piston 3. Similarly, when sliding to the air inlet 4, the air inlet 4 is blocked, and the exhaust port 5 is connected to the inside of the flexible piston 3. In addition, it is easy to understand that the number of the air inlet 4 and the exhaust port 5 can be one or more. When there are multiple ports, they are arranged on the valve body 6 at intervals along the circumferential direction.

[0029] The closed end of the flexible piston 3 is provided with a boss 301, which is used to push the valve core 7 to slide toward the exhaust port 5. When the flexible piston 3 is contracted to the limit state (i.e. Figure 1 The valve core 7 is pushed and displaced to the position of closing the exhaust port 5. One end of the valve stem 8 is connected to the boss 301. The valve stem 8 is provided with a clamp 14, which is used to push the valve core 7 to slide toward the air inlet 4. When the flexible piston 3 expands and stretches to the limit state (i.e. Figure 2 In the state shown in the figure, the valve core 7 is pushed and displaced to the position of closing the air inlet 4. In this way, the dynamic switching of air intake and exhaust is realized by the back and forth movement of the valve core 7, and there is no need to equip an independent valve, avoiding the consumption of external energy to control the opening and closing of the valve, thereby improving the energy saving effect.

[0030] It should be understood that the valve stem 8 passes through the valve core 7 but does not contact the valve core 7 to avoid increasing friction losses. In addition, those skilled in the art should know that in the case of a valve core 7, an exhaust channel should be provided on the valve core 7 to achieve exhaust. The specific form of the exhaust channel is not limited. As an option, the present embodiment provides notches 701 on both sides of the valve core 7 (see Figure 3 ) as an exhaust passage (note that the notch 701 is staggered from the air inlet 4 during installation). In other embodiments, other structures may also be used, such as providing a plurality of through holes parallel to the axis in the valve core 7.

[0031] A guide seat 13 is fixedly arranged in the valve body 6, and the valve stem 8 is slidably matched with the guide seat 13. The arrangement of the guide seat 13 enables the valve stem 8 to have two supporting points in the axial direction, thereby ensuring the stability of its movement. Furthermore, a linear bearing is arranged between the guide seat 13 and the valve stem 8 (the guide seat 13 also acts as a bearing seat), so that the valve stem 8 can move smoothly while reducing friction.

[0032] In this embodiment, the clamping head 14 is located on the side of the guide seat 13 away from the valve core 7. On this basis, a collision member 15 is provided in the valve body 6. Figure 3 In this embodiment, the collision member 15 is fixedly connected to the valve core 7 (i.e., it forms a whole with the valve core 7). In this case, the collision member 15 should pass through the guide seat 13 to ensure that the clamping head 14 can contact the collision member 15, thereby pushing the valve core 7. It is easy to understand that in this case, the collision member 15 can be a structure of multiple rods, or a structure in which one end or both ends of multiple rods are connected to a plate. The guide seat 13 should be provided with a pore, and the rod of the collision member 15 passes through the pore, while avoiding the collision member 15 from contacting the guide seat 13. In other embodiments, the collision member 15 can also be fixedly connected to the clamping head 14 (i.e., it forms a whole with the clamping head 14). In this case, the collision member 15 can be multiple rods, or one end of multiple rods is connected to a plate, and the plate is fixedly connected to the clamping head 14. Similarly, the guide seat 13 should also be provided with a pore to avoid the rod of the collision member 15.

[0033] Since the valve core 7 can slide freely, the valve core 7 may slide accidentally during the intake and exhaust processes. To this end, the present invention also makes the following improvements. Figure 1 and Figure 2 On the basis of the above, a lock core 9, a lock seat 10 and an elastic locking component are further provided. The lock core 9 is fixedly connected to one end of the valve core 7 (for example, by welding or screw connection) to form a whole with the valve core 7. Two lock grooves 901 are arranged in parallel on the lock core 9 (refer to Figure 3), the lock seat 10 is fixedly arranged. Specifically, the lock core 9 of this embodiment is fixedly connected to the end of the valve core 7 close to the flexible piston 3, and the lock seat 10 is connected to the cylinder body by screws or bolts (it is easy to understand that in other embodiments, regardless of the overall length of the piston assembly, the lock core 9 can also be fixedly connected to the end of the valve core 7 away from the flexible piston 3 in theory. In this case, the lock seat 10 is correspondingly fixedly connected to the valve body 6). The elastic locking component is arranged on the lock seat 10. The elastic locking component is inserted into one of the lock grooves 901 when the valve core 7 closes the exhaust port 5, and is inserted into the other lock groove 901 when the valve core 7 closes the air inlet 4. In this way, the elastic locking component is inserted into the corresponding lock groove 901, and the position of the lock core 9 and the valve core 7 is well defined during the process of air intake and exhaust, thereby avoiding malfunction of the valve core 7.

[0034] As an option, the elastic locking component of this embodiment includes a spring 11 and a steel ball 12. When the lock groove 901 is aligned with the steel ball 12, the steel ball 12 is inserted into the lock groove 901 under the elastic force of the spring 11. When the lock core 9 moves following the valve core 7, the steel ball 12 and the spring 11 are squeezed. The spring 11 and the steel ball 12 of this embodiment are arranged as follows: a mounting hole is arranged on the lock seat 10, and the spring 11 and the steel ball 12 are arranged in the mounting hole. At the same time, the end of the mounting hole close to the lock groove 901 should limit the steel ball 12 from falling out. In other embodiments, the spring 11 and the steel ball 12 may also be in other forms, for example, one end of the spring 11 is welded to the lock seat 10, and the other end of the spring 11 is welded to the steel ball 12.

[0035] In other embodiments, the elastic locking component may of course adopt other structures, such as a spring plunger, a torsion spring lock, etc., and the elastic locking component itself is an elastomer (such as a rubber column), which can be compressed and bent when subjected to load, and restore the deformation after the load is removed, thereby also realizing the function of locking the position of the lock cylinder 9.

[0036] In this embodiment, a pair of elastic locking components are symmetrically arranged to ensure the locking effect. Of course, in other embodiments, multiple pairs of elastic locking components can also be symmetrically arranged.

[0037] Example 2

[0038] The present embodiment provides an engine, comprising one or more variable volume piston assemblies provided in Embodiment 1, that is, the variable volume piston assembly acts as a cylinder. When multiple variable volume piston assemblies are used, the piston rods 2 in each piston assembly are connected by a transmission mechanism (such as a crankshaft connecting rod mechanism) to form a multi-cylinder engine. In actual applications, it can be applied to engines of different forms as needed, such as radial engines, V-type engines, W-type engines, in-line engines, etc.

[0039] It should be understood that when a variable volume piston assembly is used to form a single-cylinder engine, the flexible piston 3 itself should be elastic to ensure that after the flexible piston 3 expands and stretches during intake, it can automatically contract and return to the state before expansion during exhaust.

[0040] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A variable volume piston assembly, comprising a piston cylinder, a piston rod and a flexible piston with a variable volume, wherein one end of the flexible piston is open and the other end is closed, the open end is fixedly connected to the piston cylinder, the piston cylinder is provided with an air inlet and an exhaust port connected to the open end, the piston rod is connected to the closed end of the flexible piston, and is characterized in that: Also includes: The valve body is fixedly connected to the piston cylinder, and the air inlet and the air outlet are arranged on the valve body; The valve core is slidably arranged inside the valve body and is used to close the air inlet or the air outlet. The closed end of the flexible piston is provided with a boss so as to push the valve core to move to the closed air outlet when the flexible piston shrinks to the limit state. as well as One end of the valve stem is connected to the boss, and a clamp is provided on the valve stem to push the valve core to move to the closed air inlet when the flexible piston expands and stretches to the limit state.

2. The variable volume piston assembly according to claim 1, characterized in that It also includes a lock core, a lock seat and an elastic locking component. The lock core is fixedly connected to one end of the valve core. Two lock grooves are arranged in parallel on the lock core. The lock seat is fixedly arranged. The elastic locking component is arranged on the lock seat. The elastic locking component is inserted into one of the lock grooves when the valve core closes the exhaust port, and is inserted into the other lock groove when the valve core closes the air inlet.

3. The variable volume piston assembly according to claim 2, characterized in that At least one pair of elastic locking components are symmetrically arranged.

4. The variable volume piston assembly according to claim 2, characterized in that: The elastic locking component comprises a spring and a steel ball. When the locking groove is aligned with the steel ball, the steel ball is inserted into the locking groove under the elastic force of the spring.

5. The variable volume piston assembly according to any one of claims 1 to 4, characterized in that: A guide seat is fixedly arranged in the valve body, and the valve stem is slidably matched with the guide seat.

6. The variable volume piston assembly according to claim 5, characterized in that A linear bearing is arranged between the guide seat and the valve stem.

7. The variable volume piston assembly according to claim 5, characterized in that The clamping head is located at a side of the guide seat away from the valve core. A collision piece is provided in the valve body. The collision piece is fixedly connected to the valve core or the clamping head. The clamping head can pass through the guide seat to transmit the thrust of the clamping head to the valve core.

8. An engine, characterized in that: Comprising one or more variable volume piston assemblies as claimed in any one of claims 1-7.

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