CN209943443U - Automatic tensioner with gas-liquid boosting cylinder - Google Patents

Abstract

The utility model discloses an automatic tensioner with a gas-liquid boosting cylinder, which comprises a gas-liquid boosting cylinder; the gas-liquid boosting cylinder comprises a cylinder body, a serial interface wall, an oil storage tank, a left part and a right part; the left part and the right part are symmetrically arranged in the cylinder body; a serial interface wall is fixed in the middle of the cylinder body; the serial interface wall is provided with a through hole which communicates the left part with the right part; two oil storage tanks are symmetrically arranged on the cylinder body; the oil storage tank comprises an oil storage tank body and an oil storage tank piston; the left part and the right part have the same structure and respectively comprise a sealing buffer block, a guide block, a piston rod, a hydraulic cylinder piston, a cylinder barrel serial interface wall, a pneumatic cylinder piston and a stop block; the pneumatic cylinder piston, the serial interface wall and the cylinder body form a pneumatic cylinder piston cavity, and gas is arranged in the pneumatic cylinder piston cavity. The tensioner takes the compressed air in the air chamber inserted into the piston cavity of the pneumatic cylinder through the piston of the pneumatic cylinder as the main buffering damper, and the damping basically does not attenuate along with the use time, thereby ensuring the stable work of the tensioner.

Description

An automatic tensioner with a gas-liquid booster cylinder

technical field

The utility model relates to the field of hydraulic equipment, in particular to an automatic tensioner with a gas-liquid booster cylinder.

Background technique

In order to achieve the goal of energy saving and emission reduction, the automatic start-stop function of automobile engines has gradually become popular. When the car with automatic start-stop function is stopped, the engine will suspend work to save fuel; when the brake pedal is released, the engine will start again. In order to achieve a quick start of the engine, the FEAD (Front End Accessory Drive) system with an integrated starter motor/generator component used in the engine accessory drive system requires two independent tensioners or contains two The automatic tensioner of the tensioner arm tensions the belt, which is the mainstream choice today.

A FEAD system generally includes a belt, a starter motor/generator pulley, a crankshaft pulley, a driven accessory pulley, a first tensioner pulley, and a second tensioner pulley. The starter motor/generator pulley, the crankshaft pulley, the driven accessory pulley, the first tensioner pulley and the second tensioner pulley are wound by using a belt. Because the FEAD system has different working modes, the tightness of the belt will also change when the modes are switched. As an important part of the FEAD system, the automatic tensioner is mainly used to maintain the stability of the tension of the belt sections at both ends of the automatic tensioner, increase the wrap angle of the accessory pulley, compensate for the change and attenuation of the belt due to tension or wear, and compensate for the The swing of the tension arm caused by the fluctuation of the engine speed can avoid the belt slippage, noise and vibration, improve the transmission level of the system, and ensure the normal operation of the system.

At present, the existing automatic tensioners mainly include friction type and hydraulic type. The friction type automatic tensioner uses a damping element (coil spring) to provide resistance and accumulate energy for the contraction of the tight side arm, and to provide power and release energy for the extension of the loose side arm. The tensioning arm under different working conditions provides asymmetric damping. Friction-type tensioners require a large installation space, and at the same time, the damping parts will wear out with working time, resulting in damping attenuation and loss of efficacy. The hydraulic automatic tensioner generates damping by repeatedly compressing the internal oil through the damping hole, and its damping effect is longer than that of friction damping. However, it will generate a large amount of heat in the process of generating damping, which will have a thermal impact on the hydraulic components (such as one-way valves) that generate damping. The oil flowing back and forth in the hydraulic components will cause wear and tear of the hydraulic components, and the hydraulic components will fail for a long time. The document with the application number 201410462258.3 discloses a hydraulic tensioner for an engine accessory belt, which adopts a hydraulic tensioner that is widely used at present. During the process of compression and extension, the gap between the plunger and the cylinder or the one-way valve repeatedly flows in the inner and outer chambers to generate damping. Due to the use of the inner and outer chambers, the radial dimension of the automatic tensioner of this structure is large. Moreover, when the oil flows out of the gap between the plunger and the cylinder, it may cause the eccentricity of the plunger due to uneven pressure, which affects the service life of the tensioner.

Utility model content

Aiming at the deficiencies of the prior art, the technical problem to be solved by the present invention is to provide an automatic tensioner with a gas-liquid booster cylinder.

The technical solution of the utility model to solve the technical problem is to provide an automatic tensioner with a gas-liquid booster cylinder, which is characterized in that the tensioner comprises a mounting bracket and a gas-liquid booster cylinder; The force cylinder includes a cylinder block, a series dividing wall, an oil storage tank, a left part and a right part; the cylinder block is fixed on the frame body of the FEAD system through a mounting bracket; the left part and the right part are symmetrically installed inside the cylinder block; the cylinder A series dividing wall is fixed in the middle of the body; the series dividing wall is provided with a through hole to connect the left part and the right part; two oil storage tanks are symmetrically installed on the cylinder body; the oil storage tank includes an oil storage tank body and a storage tank. Oil tank piston; the left part is connected with the first tensioner pulley, and the right part is connected with the second tensioner pulley; the structure of the left and right parts is exactly the same, including a sealing buffer block, a guide block, a piston Rod, hydraulic cylinder piston, cylinder series boundary wall, pneumatic cylinder piston and stopper;

The cylinder barrel series boundary wall is installed inside the cylinder body, and the left part is a hydraulic cylinder and a pneumatic cylinder; the sealing buffer block and the cylinder body are in interference fit, and are installed at the end of the cylinder body; the guide block is connected to the cylinder body. Interference fit, close to the sealing buffer block; one end of the piston rod protrudes out of the cylinder body through the sealing buffer block and the guide block, the end is fixed with a tensioner pulley sleeve, and the middle is fixed with a hydraulic cylinder piston, through which The cylinder barrel is connected in series with the dividing wall, and the other end is fixed with a pneumatic cylinder piston; the hydraulic cylinder piston is located in the hydraulic cylinder, and the pneumatic cylinder piston is located in the pneumatic cylinder; the tensioner pulley sleeve is installed on the first tensioner through a rolling bearing The shaft end of the pulley; the stopper is fixed on the series boundary wall; the piston of the pneumatic cylinder and the stopper are matched and pre-tightened without clearance, and the piston of the pneumatic cylinder moves along the stopper; the oil storage tank body is fixed on the cylinder body , there is an oil storage tank piston inside, and the oil storage tank is divided into an oil storage tank oil cavity and an oil storage tank piston cavity; the hydraulic cylinder piston cavity is formed by the hydraulic cylinder piston, the cylinder barrel series boundary wall and the cylinder block. Cavity; the piston rod cavity of the pneumatic cylinder is a cavity formed by the pneumatic cylinder piston, the serial boundary wall of the cylinder barrel and the cylinder body; the oil liquid cavity of the oil storage tank is communicated with the piston cavity of the hydraulic cylinder through the oil passage, and the piston cavity of the oil storage tank passes through the cylinder. The air port is communicated with the pneumatic cylinder piston rod cavity; the pneumatic cylinder piston, the series boundary wall and the cylinder block form the pneumatic cylinder piston cavity, and the pneumatic cylinder piston cavity has gas.

Compared with the prior art, the beneficial effects of the present utility model are:

1. The tensioner inserts the pneumatic cylinder piston into the gas buffer chamber and compresses the gas in the gas chamber as the main buffer damping. The damping basically does not decay with the use time, and the compressed gas will not wear the working elements like the oil flow, ensuring that The stable operation of the tensioner can effectively attenuate the swing of the tensioning arm caused by the fluctuation of the engine speed as a whole.

2. The tensioner has two symmetrical tensioning arms that can cooperate with each other, namely the loose side arm and the tight side arm. When the FEAD system switches the working mode, the tension state of the belt on both sides of the starter motor/generator pulley will be converted, and the two tensioning arms can automatically make corresponding actions according to the tension state of the belt: at the tight side of the belt The tension arm (that is, the tight side arm) is compressed and fixed, and the tension arm (that is, the loose side arm) at the loose side belt stretches out for tension. In this way, the belt will not be continuously elongated due to the frequent changes of the working mode of the FEAD system, which will affect the normal operation of the drive system.

3. The utility model uses a gas-liquid booster cylinder to replace the existing coil spring. When the tight side arm contracts, damping is provided by the hydraulic cylinder piston and pneumatic cylinder piston with a certain damping, as well as the resistance of the squeezed oil and gas in the gas buffer chamber to provide damping and accumulate energy. Power is provided and energy is released by gas extrusion expansion and oil augmentation. Even if its working time is too long, there will be no mechanical wear like coil springs. In addition, when the coil spring fails and needs to be replaced, the cylinder can only be disassembled for replacement, which is time-consuming and labor-intensive. The gas-liquid booster cylinder may gradually lose the gas in the cylinder body because it cannot be completely sealed, but the gas can be supplemented through the working hole (not shown in the figure) provided on the cylinder body, which is convenient to operate.

4. The tensioner can provide greater damping for the tight side arm through the resistance of the hydraulic cylinder piston and the pneumatic cylinder piston with a certain damping, as well as the squeezed oil and gas in the gas buffer chamber, so as to automatically The hydraulic cylinder piston and the pneumatic cylinder piston with a certain damping and the squeezed gas in the piston rod cavity of the pneumatic cylinder provide a small damping for the slack arm. In this way, suitable damping can be provided for the two tensioning arms under various motor modes, so as to achieve the work effect of fast tensioning and damping of belt vibration.

5. This tensioner can be installed on the FEAD system of a hybrid vehicle internal combustion engine with a reversible generator or starter motor/generator. The gas-liquid booster cylinder can provide the power when the piston rod is tensioned and the asymmetric damping required by the piston rod in different modes, and has a long service life.

Description of drawings

1 is a layout diagram of a FEAD system in the prior art;

Fig. 2 is the transmission function diagram of the FEAD system in the generator mode in the prior art;

Fig. 3 is the transmission function diagram of the FEAD system in the prior art under the starting motor mode;

4 is a schematic diagram of the overall structure of an embodiment of the present utility model;

5 is a schematic structural diagram of a pneumatic cylinder piston according to an embodiment of the present invention;

6 is a schematic diagram of the installation of a guide block and a sealing buffer block according to an embodiment of the present invention;

In the figure: 1. FEAD system; 2. Belt; 3. Crankshaft pulley; 4. Driven accessory pulley; 5. Starter motor/generator pulley; 6. First tensioner pulley; 7. Second sheet Tensioner pulley; 8. Mounting bracket; 9. Hydraulic cylinder piston rod cavity; 10. Tensioner pulley sleeve; 11. Sealing buffer block; 12. Guide block; 13. Piston rod; 14. Hydraulic cylinder ventilation Port; 15. Hydraulic cylinder; 16. Hydraulic cylinder piston; 17. Oil port; 18. Cylinder barrel series dividing wall; 19. Oil; 20. Oil storage tank body; 21. Oil storage tank piston; 22 , air port; 23, pneumatic cylinder; 24, pneumatic cylinder piston; 25, gas buffer chamber; 26, stopper; 27, series boundary wall; 28, cylinder block; 29, pneumatic cylinder piston cavity; 30, pneumatic cylinder piston rod cavity; 31, the piston cavity of the oil storage tank; 32, the oil liquid cavity of the oil storage tank; 33, the piston cavity of the hydraulic cylinder.

Detailed ways

Specific embodiments of the present utility model are given below. The specific embodiments are only used to further describe the present invention in detail, and do not limit the protection scope of the claims of the present application.

FEAD system 1 (shown in Figure 1) includes belt 2, starter motor/generator pulley 5, crankshaft pulley 3, driven accessory pulley 4, first tensioner pulley 6 and second tensioner pulley 7. The starter motor/generator pulley 5 , the crankshaft pulley 3 , the driven accessory pulley 4 , the first tensioner pulley 6 and the second tensioner pulley 7 are wound by using the belt 2 .

The utility model provides an automatic tensioner with a gas-liquid booster cylinder (referred to as a tensioner, see FIGS. 4-6 ), which is characterized in that the tensioner includes a mounting bracket 8 and a gas-liquid booster cylinder; The gas-liquid booster cylinder includes a cylinder block 28, a series dividing wall 27, an oil storage tank, a left part and a right part; the cylinder block 28 is fixed on the frame of the FEAD system 1 through the mounting bracket 8; the starter motor/generator pulley 5 is nested inside the cylinder block 28, and the two are not in contact; the left part and the right part are symmetrically installed inside the cylinder block 28; a series dividing wall 27 is fixedly installed in the middle of the cylinder block 28; the series dividing wall 27 has through holes , the left part and the right part are communicated; two oil storage tanks are installed symmetrically on the left and right sides of the cylinder body 28, which are located at the same position on the left part and the right part; the oil storage tank includes the oil storage tank body 20 and the oil storage tank Tank piston 21; the left part is connected with the first tensioner pulley 6, and the right part is connected with the second tensioner pulley 7; the structure of the left and right parts is exactly the same, including the sealing buffer block 11, the guide block 12, piston rod 13, hydraulic cylinder piston 16, cylinder series boundary wall 18, pneumatic cylinder piston 24 and stopper 26;

Taking the left part as an example, the cylinder series dividing wall 18 is installed inside the cylinder body 28, and the left part is the hydraulic cylinder 15 and the pneumatic cylinder 23; The end of the cylinder block 28; the guide block 12 is in interference fit with the cylinder block 28, and is close to the sealing buffer block 11; the guide block 12 is used to guide and limit the piston rod 13 to avoid the contact between the piston rod 13 and the cylinder block 28 ; One end of the piston rod 13 extends out of the cylinder 28 through the sealing buffer block 11 and the guide block 12, the end is fixed with a tensioner pulley sleeve 10, and the middle is fixed with a hydraulic cylinder piston 16, passing through the cylinder The boundary wall 18 is connected in series, and the other end is fixed with a pneumatic cylinder piston 24; the hydraulic cylinder piston 16 is located in the hydraulic cylinder 15, and the pneumatic cylinder piston 24 is located in the pneumatic cylinder 23; the tensioner pulley sleeve 10 is installed on the first The shaft end of the tensioner pulley 6 is axially positioned by a nut; the stopper 26 is fixed on the series dividing wall 27; the pneumatic cylinder piston 24 is matched with the stopper 26 without clearance and pre-tightened, and the pneumatic cylinder piston 24 Move along the block 26; the oil storage tank body 20 is fixed on the cylinder body 28, and has an oil storage tank piston 21 inside, and the oil storage tank is divided into an oil storage tank oil liquid cavity 32 and an oil storage tank piston cavity 31; The hydraulic cylinder piston cavity 33 is the cavity formed by the hydraulic cylinder piston 16, the cylinder series boundary wall 18 and the cylinder block 28; the pneumatic cylinder piston rod cavity 30 is the pneumatic cylinder piston 24, the cylinder cylinder series boundary wall 18 and the cylinder. The cavity formed by the body 28; the oil tank oil cavity 32 is communicated with the hydraulic cylinder piston cavity 33 through the oil port 17, and the oil storage tank piston cavity 31 is communicated with the pneumatic cylinder piston rod cavity 30 through the air port 22; the pneumatic cylinder piston 24. The series dividing wall 27 and the cylinder block 28 form a pneumatic cylinder piston cavity 29, and the pneumatic cylinder piston cavity 29 contains gas.

The hydraulic cylinder piston 16 , the guide block 12 and the cylinder block 28 form the hydraulic cylinder piston rod cavity 9 .

Preferably, the guide block 12 is used as the cylinder wall of the hydraulic cylinder 15 on the lower side of the hydraulic cylinder 15, and a hydraulic cylinder vent 14 connected to the outside is provided near the cylinder wall of this side, so that the piston When the rod 13 is stretched, the tensioning speed will not be affected by the damping effect of the compressed gas in the piston rod cavity 9 of the hydraulic cylinder.

An even number (preferably two) blocks 26 are symmetrically distributed on both sides of the center line of the through hole of the series dividing wall 27, and the pneumatic cylinder piston cavity 29 formed by the pneumatic cylinder piston 24, the series dividing wall 27 and the cylinder block 28 is divided into several independent parts. The gas buffer chamber 25 is used to fit the pneumatic cylinder piston 24 without clearance, so that the pneumatic cylinder piston 24 can move in the gas buffer chamber 25 .

The oil storage tank piston cavity 31 is a space with dry gas, and serves as a gas capacity space for gas exchange with the pneumatic cylinder piston rod cavity 30 . The oil storage tank oil chamber 32 is a chamber with the oil 19 , and serves as a liquid capacity space for liquid exchange with the hydraulic cylinder piston chamber 33 .

Preferably, the guide block 12 is sleeved with a self-lubricating bearing, which can reduce the friction force of the piston rod 13 and facilitate sliding.

Preferably, the end of the sealing buffer block 11 in contact with the tensioner pulley sleeve 10 is an arc surface that matches the end face of the tensioner pulley sleeve 10, so as to avoid the tension between the tensioner pulley sleeve 10 and the cylinder block 28. Direct contact; the sealing buffer block 11 is made of rubber, which can slow down the impact force and reduce system noise.

Preferably, the piston rod 13 is arc-shaped; the pneumatic cylinder piston 24 has a plurality of grooves for cooperating with the block 26 without clearance, and the number of grooves is the same as that of the block 26 . The hydraulic cylinder piston 16 is an ordinary rectangle; the size of the hydraulic cylinder piston 16 is smaller than that of the pneumatic cylinder piston 24, and the specific size of the pneumatic cylinder piston 24 is related to the volume of the pneumatic cylinder 23 and the gas buffer chamber 25. The specific size of the hydraulic cylinder piston 16 The size is related to the volume of the hydraulic cylinder 15 .

Preferably, the cylinder 28 adopts a circular arc cylinder with a cylinder radian greater than a semicircle.

Preferably, the width of the hydraulic cylinder 15 is smaller than that of the pneumatic cylinder 23, because the liquid is incompressible, when the gas in the piston rod cavity 30 of the pneumatic cylinder is discharged to the piston cavity 31 of the oil storage tank, the volume of the discharged gas and the oil storage tank The volume of oil 19 discharged in 20 is relatively close. If the width of the pneumatic cylinder 23 and the hydraulic cylinder 15 are the same, the oil 19 discharged into the hydraulic cylinder piston cavity 33 is difficult to push the hydraulic cylinder piston 16 in the hydraulic cylinder 15, so that the boosting effect cannot be achieved.

Preferably, the coil spring is passed through the through hole of the series dividing wall 27, and the two ends are respectively connected with the left and right pneumatic cylinder pistons 24. The coil spring can assist with the gas-liquid booster cylinder to provide resistance for the contraction of the piston rod, and provide assistance for the expansion of the piston rod, and when the gas-liquid booster cylinder is working, the compression and extension of the coil spring can be reduced and the spring can be extended. service life.

Preferably, the center of the starter motor/generator pulley 5 coincides with the center of the tensioner (see FIG. 4 ).

The working principle and workflow of the present utility model are:

When the FEAD system 1 is in the starter motor mode (see FIG. 3 ), the starter motor/generator pulley 5 is in the starter motor pulley state and becomes the driving pulley, and the rotation direction is clockwise (clockwise in this embodiment). The belt 2 is driven by the driving pulley 5 to rotate, and the crankshaft pulley 3 and the driven accessory pulley 4 both act as driven pulleys and rotate clockwise. At this time, the belt where the second tensioner pulley 7 is located becomes loose, and the tensioner needs to be stretched to compress the belt for tensioning; the belt where the first tensioner pulley 6 is located becomes tight and compressed, and the left piston rod 13 is compressed, and the left part is the tight side arm at this time. At this time, the oil 19 existing in the piston chamber 33 of the hydraulic cylinder is pressurized and flows to the oil chamber 32 of the oil storage tank through the oil passage 17, and the volume of the oil chamber 32 of the oil storage tank is thus enlarged, thereby pushing the piston 21 of the oil storage tank to press The oil chamber 32 of the oil storage tank moves in the direction of expansion, and squeezes the gas in the piston chamber 31 of the oil storage tank to be discharged to the piston rod chamber 30 of the pneumatic cylinder through the air vent 22 . The tightness prevents oil 19 from passing through hydraulic cylinder piston 16 and gas through pneumatic cylinder piston 24 . During the shrinkage process of the piston rod 13, it will be affected by the resistance of the hydraulic cylinder piston 16 and the pneumatic cylinder piston 24 with a certain damping, the squeezed oil 19 and the gas in the gas buffer chamber 25, and the piston rod 13 shrinks slowly. , so as to attenuate the vibration of the tensioner. At this time, the belt 2 at the second tensioner pulley 7 is the loose side, and the right part is the loose side arm, and the piston rod 13 needs to be stretched to drive the second tensioner pulley 7 for tensioning. Due to the contraction of the left piston rod 13, the gas existing in the left pneumatic cylinder piston cavity 29 is pressurized and enters the right pneumatic cylinder piston cavity 29 through the through hole of the series dividing wall 27, thereby pushing the right pneumatic cylinder piston cavity 29. The piston rod 13 extends outward. At this time, the gas in the piston rod cavity 30 of the pneumatic cylinder is compressed and discharged to the piston cavity 31 of the oil storage tank, thereby pushing the piston 21 of the oil storage tank to squeeze the oil 19 in the oil liquid cavity 32 of the oil storage tank to flow to the piston cavity 33 of the hydraulic cylinder . The oil 19 squeezes the hydraulic cylinder piston 16 to provide boosting force for the piston rod 13, which speeds up the stretching speed of the piston rod 13, so that the right part can achieve the purpose of fast tensioning of the belt.

When the FEAD system 1 is in the generator mode (see FIG. 2 ), the crankshaft pulley 3 is the driving pulley, and the rotation direction is clockwise (clockwise in this embodiment), and the starter motor/generator pulley 5 is at this time. Generator pulley status. Driven by the belt 2, the driven accessory pulley 4 and the starter motor/generator pulley 5 both act as driven pulleys and rotate clockwise. At this time, the belt where the first tensioner pulley 6 is located becomes loose, and a tensioner is required. Stretch to compress the belt for tensioning; the belt where the second tensioner pulley 7 is located becomes tight and is compressed, the right piston rod 13 is compressed, and the right part is the tight side arm at this time. At this time, the oil 19 existing in the piston chamber 33 of the hydraulic cylinder is pressurized and flows to the oil chamber 32 of the oil storage tank through the oil passage 17, and the volume of the oil chamber 32 of the oil storage tank is thus enlarged, thereby pushing the piston 21 of the oil storage tank to press The oil chamber 32 of the oil storage tank moves in the direction of expansion, and squeezes the gas in the piston chamber 31 of the oil storage tank to be discharged to the piston rod chamber 30 of the pneumatic cylinder through the air vent 22 . The tightness prevents oil 19 from passing through hydraulic cylinder piston 16 and gas through pneumatic cylinder piston 24 . During the shrinkage process of the piston rod 13, it will be affected by the resistance of the hydraulic cylinder piston 16 and the pneumatic cylinder piston 24 with a certain damping, the squeezed oil 19 and the gas in the gas buffer chamber 25, and the piston rod 13 shrinks slowly. , so as to attenuate the vibration of the tensioner. At this time, for the left part of the tensioner, the belt 2 at the first tensioner pulley 6 is the loose edge at this time, and the left part is the loose edge arm, and the piston rod 13 needs to be stretched to drive the first tensioner pulley 6 to stretch tight. Due to the contraction of the right piston rod 13, the gas existing in the right pneumatic cylinder piston cavity 29 is pressurized and enters the left pneumatic cylinder piston cavity 29 through the through hole of the series dividing wall 27, thereby pushing the left pneumatic cylinder piston cavity 29. The piston rod 13 extends outward. At this time, the gas in the piston rod cavity 30 of the pneumatic cylinder is compressed and discharged to the piston cavity 31 of the oil storage tank, thereby pushing the piston 21 of the oil storage tank to squeeze the oil 19 in the oil liquid cavity 32 of the oil storage tank to flow to the piston cavity 33 of the hydraulic cylinder . The oil 19 squeezes the hydraulic cylinder piston 16 to provide boosting force for the piston rod 13, accelerate the stretching speed of the piston rod 13, and make the left part achieve the purpose of quickly tensioning the belt.

Because in each working mode of the FEAD system, there is a loose edge as well as a tight edge, so the working process of the left and right parts of the tensioner is correspondingly opposite. For example, when the left piston rod 13 is retracted, the corresponding right piston rod 13 is extended.

The points not mentioned in the present invention are applicable to the prior art.

Claims (10)

1. An automatic tensioner with a gas-liquid booster cylinder, characterized in that the tensioner comprises a mounting bracket and a gas-liquid booster cylinder; the gas-liquid booster cylinder comprises a cylinder block, a series boundary wall, an oil storage Tank, left part and right part; the cylinder body is fixed on the frame body of the FEAD system through the mounting bracket; the left part and the right part are symmetrically installed inside the cylinder body; a series dividing wall is fixed in the middle of the cylinder body; There is a through hole to communicate the left part and the right part; two oil storage tanks are symmetrically installed on the cylinder body; the oil storage tank includes an oil storage tank tank body and an oil storage tank piston; the left part is connected to the first tensioner The pulley is connected, and the right part is connected with the second tensioner pulley; the structure of the left part and the right part are exactly the same, including a sealing buffer block, a guide block, a piston rod, a hydraulic cylinder piston, and a cylinder series boundary wall , Pneumatic cylinder piston and stop; The cylinder barrel series boundary wall is installed inside the cylinder body, and the left part is a hydraulic cylinder and a pneumatic cylinder; the sealing buffer block and the cylinder body are in interference fit, and are installed at the end of the cylinder body; the guide block is connected to the cylinder body. Interference fit, close to the sealing buffer block; one end of the piston rod protrudes out of the cylinder body through the sealing buffer block and the guide block, the end is fixed with a tensioner pulley sleeve, and the middle is fixed with a hydraulic cylinder piston, through which The cylinder barrel is connected in series with the dividing wall, and the other end is fixed with a pneumatic cylinder piston; the hydraulic cylinder piston is located in the hydraulic cylinder, and the pneumatic cylinder piston is located in the pneumatic cylinder; the tensioner pulley sleeve is installed on the first tensioner through a rolling bearing The shaft end of the pulley; the stopper is fixed on the series boundary wall; the piston of the pneumatic cylinder and the stopper are matched and pre-tightened without clearance, and the piston of the pneumatic cylinder moves along the stopper; the oil storage tank body is fixed on the cylinder body , there is an oil storage tank piston inside, and the oil storage tank is divided into an oil storage tank oil chamber and an oil storage tank piston chamber; the hydraulic cylinder piston chamber is a cavity formed by a hydraulic cylinder piston, a series boundary wall of the cylinder barrel and a cylinder block. ;The piston rod cavity of the pneumatic cylinder is the cavity formed by the pneumatic cylinder piston, the series boundary wall of the cylinder barrel and the cylinder body; the oil liquid cavity of the oil storage tank is communicated with the piston cavity of the hydraulic cylinder through the oil passage, and the piston cavity of the oil storage tank passes through the ventilation port. It is communicated with the piston rod cavity of the pneumatic cylinder; the piston of the pneumatic cylinder, the series boundary wall and the cylinder body form the piston cavity of the pneumatic cylinder, and the piston cavity of the pneumatic cylinder has gas. 2 . The automatic tensioner with a gas-liquid booster cylinder according to claim 1 , wherein the hydraulic cylinder piston, the guide block and the cylinder body form a hydraulic cylinder piston rod cavity. 3 . 3. The automatic tensioner with a gas-liquid booster cylinder according to claim 2, wherein the lower side of the hydraulic cylinder is used as the cylinder wall of the hydraulic cylinder by a guide block, and the cylinder is close to this side. A hydraulic cylinder vent connected to the outside is arranged on the body wall, and the tensioning speed will not be affected by the damping effect of the compressed gas in the piston rod cavity of the hydraulic cylinder when the piston rod is stretched. 4. The automatic tensioner with a gas-liquid booster cylinder according to claim 1, characterized in that the even-numbered blocks are symmetrically distributed on both sides of the center line of the through hole of the series boundary wall, and the pneumatic cylinder piston cavity is divided into two parts. Several independent gas buffer chambers are used to fit the pneumatic cylinder piston without clearance, so that the pneumatic cylinder piston can move in the gas buffer chamber. 5. The automatic tensioner with a gas-liquid booster cylinder according to claim 1, wherein the oil storage tank piston cavity is a space with dry gas, which is used as a space between the gas capacity space and the piston rod cavity of the pneumatic cylinder. Gas exchange; the oil liquid cavity of the oil storage tank is a cavity with oil liquid, which is used as a liquid capacity space to exchange liquid with the piston cavity of the hydraulic cylinder. 6. The automatic tensioner with a gas-liquid booster cylinder according to claim 1, wherein the guide block is sleeved with a self-lubricating bearing, which can reduce the friction force of the piston rod and facilitate sliding. 7 . The automatic tensioner with a gas-liquid booster cylinder according to claim 1 , wherein the end of the sealing buffer block in contact with the tensioner pulley sleeve is the end face of the tensioner pulley sleeve. 8 . The matching arc surface avoids the direct contact between the tensioner pulley sleeve and the cylinder body; the sealing buffer block is made of rubber. 8. The automatic tensioner with a gas-liquid booster cylinder according to claim 1, wherein preferably, the piston rod is arc-shaped; the pneumatic cylinder piston has several grooves for connecting with the stopper No clearance fit, the number of grooves is the same as the number of stops; the size of the hydraulic cylinder piston is smaller than that of the pneumatic cylinder piston. 9 . The automatic tensioner with a gas-liquid booster cylinder according to claim 1 , wherein the width of the hydraulic cylinder is smaller than that of the pneumatic cylinder. 10 . 10. The automatic tensioner with a gas-liquid booster cylinder according to claim 1, characterized in that the coil spring is passed through the through hole of the series dividing wall, and the two ends are respectively connected with the left and right pneumatic cylinder pistons. connect.

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