Vehicle gear shifting buffer device, hydraulic control system and gearbox assembly

Abstract

The utility model discloses a vehicle gear shifting buffer device, a hydraulic control system and a gearbox assembly. The bidirectional buffer comprises a cavity, an elastic piece, a first piston and a second piston, wherein the elastic piece, the first piston and the second piston are located in the cavity. The first piston and the second piston are fixedly connected with the two ends of the elastic piece correspondingly and divide the cavity into an advancing cavity and a retreating cavity. The middle of the elastic piece is fixed in the cavity, the two ends of the elastic piece are free ends, the elastic piece can slide in the cavity in cooperation with the first piston and the second piston, and power crossing in the gear switching process can be reduced, so that more gentle gear shifting is achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of forklift hydraulic gearbox, concretely to a vehicle gear shifting buffer device, hydraulic control system and gearbox assembly. BACKGROUND

[0002] The use scene determines that the forklift needs to frequently shift gears and reverse in the actual working process, and the smoothness and softness of gear shifting are very important for driving performance. The forklift realizes gear engagement or disengagement to transmit gear torque and switch gears by the engagement and disengagement of the driving and driven friction plates of the clutch. The return of the clutch piston of the gearbox is realized by the pre-tightening force of the spring in the clutch. In the instant of gear shifting, the gear clutch is impacted by the rapid engagement of the driving and driven friction plates due to the excessive main oil pressure overcoming the pre-tightening force of the clutch spring. In addition, due to the characteristics of the electromagnetic switch valve used in the gearbox gear shifting and the gaps of the gear, main reducer and bevel gear, the rapid oil filling not only causes the driving jerk, but also causes additional impact and wear of the whole vehicle transmission system, affecting the vehicle performance, reliability and service life.

[0003] In the prior art, the utility model with the patent number CN118517521A discloses a kind of hydraulic control system and hydraulic control method of hybrid power transmission, and in the patent, stable pressure accumulator is connected with clutch pressure control port, and stable pressure accumulator is connected with clutch pressure control port.The elastic deformation and gas compressibility in the inside of stable pressure accumulator are used to stabilize the working pressure of system. Stable pressure accumulator is like a buffer, which reduces the pressure fluctuation and impact in the hydraulic system, and improves the stability and reliability of the system. However, gas pressure accumulator is a very mature solution, which is frequently used in various hydraulic systems to solve the problem of pressure fluctuation and impact in the hydraulic system. UTILITY MODEL CONTENTS

[0004] The technical problem to be solved by the utility model is to solve the gear shifting impact problem of vehicle hydraulic gearbox.

[0005] To solve the above technical problems, the utility model provides the following technical scheme:

[0006] A vehicle gear shifting buffer device, comprising: a bidirectional buffer 4; the bidirectional buffer 4 comprises a cavity 41, and an elastic member 42, a first piston 43 and a second piston 44 located in the cavity 41;

[0007] The first piston 43 and the second piston 44 are respectively fixed with the two ends of the elastic member 42 and divide the cavity 41 into a forward cavity 45 and a reverse cavity 46; the elastic member 42 cooperates with the first piston 43 and the second piston 44, so that the first piston 43 and the second piston 44 can slide in the cavity 41.

[0008] In one embodiment of the utility model, when in use, the bidirectional buffer 4 is connected in series to the oil circuits of the forward clutch 1 and the reverse clutch 2 .

[0009] The utility model also provides a vehicle hydraulic control system, which applies the above-mentioned vehicle shift buffer device.

[0010] The utility model also provides a transmission assembly, which is applied with the above-mentioned vehicle hydraulic control system.

[0011] Compared with the prior art, the beneficial effects of the present invention are:

[0012] The bidirectional buffer used in this utility model can buffer the gear oil pressure, increase the fault tolerance of oil pressure fluctuations during gear shifts, reduce the rapid clutch engagement caused by oil pressure fluctuations and rapid gear shifting, and achieve more stable and reliable gear changes, avoiding the jerking caused by impact. The vehicle's NVH will be greatly improved, and the driver's driving comfort and driving quality will also be improved. Note: Vehicle NVH refers to noise, vibration, and harshness.

[0013] The bidirectional buffer adopts an integrated bidirectional structure and uses the oil pressure of the opposite gear as an auxiliary. While buffering the gear oil pressure, during the forward gear stamping process, it uses the residual oil pressure in the reverse gear clutch to buffer the forward gear stamping process, and uses the forward gear oil pressure to push the bidirectional buffer to accelerate the reverse gear pressure relief, and vice versa.

[0014] The bidirectional buffer used in the utility model can buffer the oil pressure, realize smoother gear shifting, and reduce the impact on product function and reliability caused by the impact wear of mechanical parts.

[0015] The hydraulic control system designed in this utility model cancels the traditional front single-acting accumulator and connects an innovatively designed integrated bidirectional buffer in series between the forward clutch and the reverse clutch, thereby reducing the gear shift shock caused by power cross-over due to insufficient pressure relief.

[0016] The bidirectional buffer proposed by the utility model does not have the airbag device of the traditional pneumatic accumulator, does not require an air valve or inflation, and does not simply connect two pneumatic accumulators in series. The bidirectional buffer innovatively proposes an integrated bidirectional structure, which saves the layout space of the engine compartment of a small-tonnage internal combustion forklift.

[0017] The hydraulic system designed in this utility model eliminates the gear shift shock, avoids the burning of friction plates caused by human irregular operating habits, achieves a comfortable, stable and fast transmission effect, and makes the forklift have more humane driving and operating performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of a vehicle gear shift buffer device according to an embodiment of the present utility model.

[0019] Figure 2 This is a schematic diagram of a vehicle hydraulic control system according to an embodiment of the present utility model.

[0020] Figure 3 This is a simplified forklift hydraulic control system and a comparative schematic diagram of an embodiment of the present utility model.

[0021] Figure 4 This is a simulation diagram of a forklift hydraulic control system according to an embodiment of the present utility model.

[0022] Figure 5 Schematic diagram of simulation results of an embodiment of the present utility model.

[0023] Figure 6 This is a schematic diagram of a gearbox assembly according to an embodiment of the present utility model. DETAILED DESCRIPTION

[0024] In order to facilitate those skilled in the art to understand the technical solution of the present invention, the technical solution of the present invention is further described in conjunction with the accompanying drawings.

[0025] The terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0026] Example 1

[0027] See also Figure 1 As shown, the present invention provides a vehicle shift buffer device, comprising a bidirectional buffer 4. The bidirectional buffer 4 comprises a cavity 41, and an elastic member 42, a first piston 43 and a second piston 44 located in the cavity 41.

[0028] The first piston 43 and the second piston 44 are respectively fixed to the ends of the elastic member 42, and divide the cavity 41 into a forward cavity 45 and a backward cavity 46. The elastic member 42 cooperates with the first piston 43 and the second piston 44, allowing the first piston 43 and the second piston 44 to slide in the cavity 41.

[0029] In this embodiment, the elastic member 42 is, for example, a spring, and the elastic member 42 is not fixed to the cavity 41. Furthermore, the inner wall of the cavity 41 also serves as a guide for the first piston 43 and the second piston 44 to slide.

[0030] Please participate Figure 1 and Figure 2 As shown, in one embodiment of the present invention, when in use, the bidirectional buffer 4 is connected in series to the oil circuits of the forward clutch 1 and the reverse clutch 2.

[0031] Example 2

[0032] Please participate Figure 1 and Figure 2 As shown, the present invention also provides a vehicle hydraulic control system, which applies the vehicle shift buffer device described in Example 1.

[0033] This embodiment uses a hydraulic control system for a small-tonnage forklift as an example. The hydraulic control system includes a forward clutch 1, a reverse clutch 2, an inching valve 3, and a solenoid reversing valve 5. The shift oil circuit passes through the inching valve 3 and the solenoid reversing valve 5 before entering the forward clutch 1 and reverse clutch 2, respectively. Furthermore, a bidirectional buffer 4 is connected in series with the oil circuits entering the forward clutch 1 and reverse clutch 2.

[0034] See also Figure 2 As shown, in one embodiment of the present invention, the hydraulic control system further includes an oil tank 61, a coarse oil filter 62, and an oil pump 63. The oil in the oil tank 61 is filtered by the coarse oil filter 62 and then pressurized by the oil pump 63 before being divided into two paths at the outlet: one path for shifting oil and the other for speed change oil.

[0035] In one embodiment of the present invention, the hydraulic control system includes a main pressure regulating valve 71, a fine oil filter 72, a torque converter 73, a safety valve 74, a relief valve 75, and a radiator 76. In the transmission oil circuit, hydraulic oil passes through the main pressure regulating valve 71 and the fine oil filter 72 in sequence before entering the torque converter 73. The safety valve 74 is located in the transmission oil circuit between the fine oil filter 72 and the torque converter 73. The inlet and outlet oil circuits of the relief valve 75 are connected to the inlet and outlet oil circuits of the fine oil filter 72. The high-temperature transmission oil that passes through the torque converter 73 is cooled by the radiator 76 and then returned to the bottom of the oil tank 61.

[0036] See also Figure 1 、 2 As shown, in one embodiment of the present invention, the shift buffering of the bidirectional buffer 4 works as follows:

[0037] During the gear shifting from forward to reverse, the electromagnetic reversing valve 5 works, the Y2 side channel of the electromagnetic reversing valve 5 loses electricity, the Y1 side channel obtains electricity, the electromagnetic reversing valve 5 is switched from the Y2 side channel connection to the Y1 side channel connection, and the transmission oil of the electromagnetic reversing valve 5 and the micro valve 3 is buffered by the bidirectional buffer 4 and enters the reverse clutch 2.

[0038] At this time, the forward clutch 1 is depressurized, the hydraulic oil in the forward cavity 45 continues to decrease, and the hydraulic oil enters the reverse cavity 46, and the first piston 43 and the second piston 44 reciprocate in the cavity 41 under the action of the hydraulic oil in the forward cavity 45 and the reverse cavity 46, so that the hydraulic oil in the forward cavity 45 is used as the buffer of the oil pressure in the reverse cavity 46 and pushes the oil pressure in the reverse cavity 46, and the oil pressure in the reverse gear is accelerated, and the forward gear is depressurized. In the gear shifting from reverse to forward, the same is true.

[0039] In the embodiment, during the gear shifting from forward to reverse, the forward gear clutch 6 is depressurized, the forward clutch 1 can be quickly depressurized in the process that the reverse clutch 2 is buffered and pressurized under the action of the bidirectional buffer 4, the gear shifting is quickly and effectively realized, and power cross is reduced. In the embodiment, the power cross means that the forward gear and the reverse gear work at the same time, that is, during the pressurization of the reverse gear, the forward gear pressure still has oil pressure residues, and vice versa.

[0040] In an embodiment of the utility model, the gear shifting buffer further includes: in the case of hanging forward gear from neutral gear, the electromagnetic reversing valve 5 works, the Y2 side channel obtains electricity and is connected, the transmission oil of the electromagnetic reversing valve 5 and the micro valve 3 is buffered by the forward cavity 45 and the first piston 43 and enters the forward clutch 1, the forward clutch 1 is engaged, and the forward gear is realized, and the same is true for hanging reverse gear from neutral gear.

[0041] In one embodiment of the present invention, when the inching function is engaged, the driver depresses the inching pedal, which mechanically drives the valve stem of the inching valve 3. After reaching a certain travel distance, the oil in the main pressure line and the clutch is bypassed and released into the oil pan, reducing or shutting off clutch pressure and achieving the inching function. To exit the inching function, the driver releases the inching pedal, which mechanically drives the valve stem of the inching valve 3 back to its original position, allowing the main oil pressure and clutch oil pressure to quickly recover. During the inching function, the bidirectional buffer 4 assists in reducing clutch pressure. During the exit from the inching function, the bidirectional buffer 4 also acts as a buffer, preventing gear shock caused by the rapid release of the inching pedal. In this embodiment, the clutch refers to the forward clutch 1 or the reverse clutch 2, and the inching valve 3 is used in conjunction with the forward clutch 1 or the reverse clutch 2. The inching function refers to the fact that after depressing the inching pedal, the gear oil pressure is appropriately reduced according to the pedal opening, thereby reducing the amplitude of the transmitted power and ultimately achieving the effect of inching the vehicle. This appropriate reduction in gear oil pressure can be understood as the same principle as the oil leakage in a normal gear.

[0042] In one embodiment of the present invention, two sets of forklift hydraulic control systems are simulated using professional hydraulic simulation software. One set is the forklift hydraulic control system of the present invention, and the other set of forklift hydraulic control system is based on the forklift hydraulic control system of the present invention, with the two-way buffer 4 removed. While keeping the others unchanged, a traditional accumulator 4A is added, and according to the conventional setting of the accumulator 4A, it is set in the oil circuit between the micro valve 3 and the electromagnetic reversing valve 5 as a comparative example. In addition, since the gear shift shock is mainly related to the oil pressure change during the gear shift process, the hydraulic circuits such as the wet clutch and the torque converter inside the gearbox are not the main focus, so the hydraulic principle is simplified. In the simulation environment, a single-piston rod cylinder with spring return is used instead of the wet clutch, and other hydraulic circuits including the torque converter are removed. For details, please refer to Figure 3 shown.

[0043] In one embodiment of the present invention, in the simulation environment, since the innovatively designed bidirectional buffer 4 is a non-standard hydraulic component, there is no standard component library in the simulation software that can be directly called. Therefore, the hydraulic component HCD module is used to build a bidirectional buffer component according to the actual parameters. Figure 3 The simulation model built is as follows Figure 4 shown. Figure 4 In the figure, the left side is the forklift hydraulic control system where the accumulator 4A is located, and the right side is the forklift hydraulic control system where the bidirectional buffer 4 is located.

[0044] In one embodiment of the present invention, simulation is performed based on modeling, and the results are as follows Figure 5As shown. Analyzing the simulation results, at the moment of shifting, at point ① in the figure, the instantaneous oil pressure fluctuation of the gear of the utility model (solid line in the curve diagram) is greatly suppressed, the gear oil pressure stamping time is relatively slowed down by 40%, the slope of the oil pressure rising curve is reduced and smoother, and after holding pressure (at point ② in the figure), the gear oil pressure of the new scheme is smoother. During the shifting process, the utility model buffers the gear oil pressure due to the two-way buffer 4, slows down the fluctuation of the oil pressure at the moment of shifting, slows down the pressure rise curve, and allows the gear to be engaged smoothly and quickly. After holding pressure, the fluctuation of the oil pressure is also filtered to ensure the stability of the gear oil pressure.

[0045] See also Figure 6 As shown, the present invention also provides a transmission assembly, which uses the vehicle hydraulic control system described in Example 2.

[0046] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the foregoing description. It is intended that all variations within the meaning and range of equivalents of the claims be encompassed within the present invention, and any reference numerals in the claims should not be construed as limiting the claims to which they relate.

[0047] The above-mentioned embodiments only represent the implementation methods of the utility model. The protection scope of the utility model is not limited to the above-mentioned embodiments. For those skilled in the art, several modifications and improvements can be made without departing from the concept of the utility model, which all fall within the protection scope of the utility model.

Claims

1. A vehicle shift buffer device, characterized in that: The invention comprises a bidirectional buffer (4); the bidirectional buffer (4) comprises a cavity (41), and an elastic member (42), a first piston (43) and a second piston (44) located in the cavity (41); the first piston (43) and the second piston (44) are respectively fixed to two ends of the elastic member (42) and divide the cavity (41) into a forward cavity (45) and a backward cavity (46); the elastic member (42) cooperates with the first piston (43) and the second piston (44) to enable the first piston (43) and the second piston (44) to slide in the cavity (41).

2. The vehicle shift buffer device according to claim 1, characterized in that: When in use, the bidirectional buffer (4) is connected in series to the oil circuits of the forward clutch (1) and the reverse clutch (2).

3. A vehicle hydraulic control system, characterized in that: A vehicle gear shift buffer device according to any one of claims 1-2 is used.

4. A gearbox assembly, characterized in that: The vehicle hydraulic control system according to claim 3 is applied.

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