An automatic return device based on a cam mechanism

Abstract

This utility model provides an automatic return device based on a cam mechanism, comprising: a base plate fixed to a pump body at the end of a displacement control shaft; a cam mechanism fixed to the displacement control shaft and circumferentially connected thereto, the outer circumferential surface of the cam mechanism having a V-groove; a slider mechanism, one end of which is rotatably connected to the base plate, and the other end extending into the V-groove and rollingly connected thereto, wherein when the displacement control shaft is in the return-to-center state, the slider mechanism is located at the bottom center of the V-groove; and a reset mechanism connected between the slider mechanism and the pump body, applying a preset pulling force to the slider mechanism to maintain contact between the slider mechanism and the V-groove.

Description

Technical Field

[0001] This utility model relates to the field of engineering machinery operation and control technology, and in particular to an automatic return device based on a cam mechanism. Background Technology

[0002] Mechanical control devices, as a traditional control method, are widely used in engineering machinery. Their basic principle is that the control handle is connected to the hydraulic pump's displacement control mechanical shaft. When the operator moves the control handle, it drives the displacement control mechanical shaft to rotate, thereby controlling the working state of the hydraulic system and the actions of the actuators.

[0003] However, if the hydraulic pump's displacement control mechanical shaft cannot return to the neutral position smoothly after the operator stops operating, it will cause deviation in the operator's control of the equipment, making the equipment's movement trajectory inconsistent with the operating intention. This will not only affect the accuracy of the operation but may also cause a decline in the quality of the operation and even lead to a safety accident. Utility Model Content

[0004] Therefore, the purpose of this utility model is to provide an automatic return device based on a cam mechanism to solve the technical problem in the prior art that the mechanical shaft controlling the displacement of the hydraulic pump cannot return to the neutral position smoothly.

[0005] To achieve the above objectives, this utility model provides an automatic return device based on a cam mechanism, comprising:

[0006] The base plate is fixed to the pump body at the end of the displacement control shaft;

[0007] A cam mechanism is fixed on the displacement control shaft and circumferentially connected to it, and the outer circumferential surface of the cam mechanism is provided with a V-groove.

[0008] A slider mechanism, one end of which is rotatably connected to the base plate, and the other end extends into the V-groove and is rolledly connected thereto. When the displacement control shaft is in the center-back state, the slider mechanism is located at the bottom center of the V-groove.

[0009] A reset mechanism is connected between the slider mechanism and the pump body, and applies a preset tension to the slider mechanism to keep the slider mechanism in contact with the V-groove.

[0010] Furthermore, the cam mechanism includes a pump shaft retaining plate and a cam plate with a V-groove, the pump shaft retaining plate and the cam plate being connected by bolts.

[0011] Furthermore, the pump shaft clamping plate is provided with a first through hole that is adapted to the shape of the displacement control shaft, the side of the first through hole is provided with a clamping notch, and the opening of the clamping notch is provided with a second through hole perpendicular to the axial direction of the first through hole.

[0012] Furthermore, the base plate includes a fixed part connected to the pump body and an extension part extending away from the displacement control shaft, wherein the angle between the axis of the extension part and the centerline of the V-groove is less than or equal to 90°.

[0013] Furthermore, the slider mechanism includes a push rod, a bearing connecting rod, and a bearing. One end of the push rod is rotatably connected to the base plate, and the other end is fixedly connected to the bearing connecting rod. The bearing is connected to the bearing connecting rod.

[0014] Furthermore, the reset mechanism includes a tension spring and a bolt, with one end of the tension spring connected to the bearing connecting rod and the other end connected to the pump body via the bolt.

[0015] Compared with the prior art, the beneficial effects of this utility model are:

[0016] This utility model discloses an automatic return device based on a cam mechanism. When the operator reduces or releases the operating force, the reset mechanism drives the end of the slider mechanism connected to the V-groove to move towards the bottom center of the V-groove, thus returning the displacement control shaft to the neutral position. This mechanical structure is simple and reliable, effectively solving the technical problem in existing technologies where the displacement control mechanical shaft of a hydraulic pump cannot smoothly return to the neutral position, improving operational accuracy and equipment safety. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the automatic return device based on a cam mechanism according to this utility model.

[0018] Figure 2 This is a schematic diagram of the structure of the base plate of this utility model;

[0019] Figure 3 This is a schematic diagram of the cam mechanism of this utility model;

[0020] Figure 4 This is a schematic diagram of the slider mechanism of this utility model;

[0021] Figure 5 This is a schematic diagram of the reset mechanism of this utility model;

[0022] In the picture:

[0023] 1. Base plate;

[0024] 2. Cam mechanism; 21. Pump shaft retaining plate; 22. Cam plate; 211. First through hole; 212. Clamping notch; 213. Second through hole;

[0025] 3. Slider mechanism; 31. Push rod; 32. Bearing connecting rod; 33. Bearing;

[0026] 4. Reset mechanism; 41. Tension spring; 42. Bolt. Detailed Implementation

[0027] To facilitate understanding of this utility model, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0028] The present invention will now be described in detail. In the following paragraphs, different aspects of the embodiments are defined in more detail. These aspects may be combined with any other aspect or multiple aspects unless explicitly stated otherwise. In particular, any feature considered preferred or advantageous may be combined with one or more other features considered preferred or advantageous.

[0029] In the description of this utility model, it should be understood that the terms "inner", "outer", "upper", "lower", "left" and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and do not indicate or imply that the device referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this utility model.

[0030] refer to Figure 1 As shown, this utility model discloses an automatic return device based on a cam mechanism, used to drive the hydraulic pump's displacement control mechanical shaft back to the neutral position after the operator stops the operation. The automatic return device based on the cam mechanism includes:

[0031] Base plate 1 is fixed to the pump body at the end of the displacement control shaft;

[0032] Cam mechanism 2 is fixed on the displacement control shaft and circumferentially connected to it. The outer circumferential surface of cam mechanism 2 is provided with a V-groove.

[0033] The slider mechanism 3 has one end rotatably connected to the base plate 1, and the other end extends into the V-groove and is rolledly connected thereto. When the displacement control shaft is in the return-to-center state, the slider mechanism 3 is located at the bottom center of the V-groove.

[0034] The reset mechanism 4 is connected between the slider mechanism 3 and the pump body, and applies a preset tension to the slider mechanism 3 to keep the slider mechanism 3 in contact with the V-groove.

[0035] The specific connection method between the base plate 1 and the pump body can be selected according to actual needs. For example, the base plate 1 can be fixed to the pump body using pump shaft fastening bolts.

[0036] In this embodiment, the cam mechanism 2 is fixed to the displacement control shaft and circumferentially connected to it. When the operator moves the handle, the cam mechanism 2 drives the displacement control shaft to rotate. The end of the slider mechanism 3 connected to the V-groove rolls along the inner wall of the V-groove. At this time, the preset tension applied to the slider mechanism 3 by the reset mechanism 4 increases. When the operator stops moving the handle, the reset mechanism 4 drives the end of the slider mechanism 3 connected to the V-groove to move towards the bottom center of the V-groove, causing the displacement control shaft to return to the neutral position. This mechanical structure is simple and reliable, effectively solving the technical problem in the prior art that the displacement control mechanical shaft of the hydraulic pump cannot smoothly return to the neutral position, improving the accuracy of operation and equipment safety.

[0037] refer to Figure 2 As shown, in some embodiments, the base plate 1 includes a fixed part connected to the pump body and an extension part extending in a direction away from the displacement control shaft, wherein the angle between the axis of the extension part and the centerline of the V-groove is less than or equal to 90°.

[0038] refer to Figure 3 As shown, in some embodiments, the cam mechanism 2 includes a pump shaft retaining plate 21 and a cam plate 22, which are connected by bolts. The cam plate 22 is a rigid metal plate with a V-groove. The pump shaft retaining plate 21 has a first through hole 211 adapted to the shape of the displacement control shaft. The side of the first through hole 211 has a clamping notch 212, and the opening of the clamping notch 212 has a second through hole 213 perpendicular to the axial direction of the first through hole 211. Preferably, the displacement control shaft is a square shaft, and the first through hole 211 is a square hole corresponding to the square shaft. After the first through hole 211 is fitted onto the displacement control shaft, bolts are passed through the second through hole 213 and tightened, making the clamping notch 212 smaller, thereby securing the pump shaft retaining plate 21 to the displacement control shaft and fixing it axially to the displacement control shaft.

[0039] refer to Figure 4 As shown, in some embodiments, the slider mechanism 3 includes a push rod 31, a bearing connecting rod 32, and a bearing 33. One end of the push rod 31 is rotatably connected to the base plate 1, and the other end is fixedly connected to the bearing connecting rod 32. The bearing 33 is connected to the bearing connecting rod 32. One end of the bearing connecting rod 32 has an external thread, and the other end is a short rod with an internal thread and a shoulder. The externally threaded end of the bearing connecting rod 32 is connected to the threaded hole of the push rod 31; the bearing 33 is fitted onto the shoulder of the bearing connecting rod 32 and connected to the internally threaded end of the bearing connecting rod 32 by bolts and a limiting member, thereby restricting the axial movement of the bearing 33.

[0040] refer to Figure 5 As shown, in some embodiments, the reset mechanism 4 includes a tension spring 41 and a bolt 42. One end of the tension spring 41 is connected to the bearing connecting rod 32, and the other end is connected to the pump body via the bolt 42. The reset mechanism 4 provides elasticity to keep the bearing 33 in continuous contact with the cam plate 22.

[0041] Preferably, bolt 42 is an extended bolt, which replaces one bolt on the pump body and serves to fix both the pump casing and the traction spring 41.

[0042] During equipment operation, when the operator moves the handle, the cam mechanism 2 acts as the driving element, and the slider mechanism 3 acts as the driven element. The cam mechanism 2 drives the displacement control shaft to rotate, while the cam plate 22 pushes the bearing 33 of the slider mechanism 3 to roll along the inner wall of the V-groove from the middle of the bottom of the V-groove to one side. The tension spring 41 of the reset mechanism 4 is stretched, accumulating elastic potential energy. When the operator reduces the operating force or releases the operating force, the tension spring 41 releases its elastic potential energy and drives the bearing 33 of the slider mechanism 3 to roll from one side of the bottom of the V-groove to the middle. At this time, the slider mechanism 3 acts as the driving element, and the cam mechanism 2 acts as the driven element. When the slider mechanism 3 moves to the middle of the bottom of the V-groove 221, the movement stops, driving the displacement control shaft back to the neutral position.

[0043] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. An automatic return device based on a cam mechanism, characterized in that, include: The base plate (1) is fixed on the pump body at the end of the displacement control shaft; A cam mechanism (2) is fixed on the displacement control shaft and circumferentially connected to it. The outer circumferential surface of the cam mechanism (2) is provided with a V-groove. The slider mechanism (3) has one end rotatably connected to the base plate (1) and the other end extends into the V-groove and is rolledly connected thereto. When the displacement control shaft is in the center-back state, the slider mechanism (3) is located at the bottom center of the V-groove. The reset mechanism (4) is connected between the slider mechanism (3) and the pump body, and applies a preset tension to the slider mechanism (3) to keep the slider mechanism (3) in contact with the V-groove.

2. The automatic return device based on a cam mechanism according to claim 1, characterized in that, The cam mechanism (2) includes a pump shaft retainer plate (21) and a cam plate (22) with a V-groove, which are connected by bolts.

3. The automatic return device based on a cam mechanism according to claim 2, characterized in that, The pump shaft clamping plate (21) is provided with a first through hole (211) that is adapted to the shape of the displacement control shaft. The side of the first through hole (211) is provided with a clamping notch (212). The opening of the clamping notch (212) is provided with a second through hole (213) perpendicular to the axial direction of the first through hole (211).

4. The automatic return device based on a cam mechanism according to claim 1, characterized in that, The base plate (1) includes a fixed part connected to the pump body and an extension part extending away from the displacement control shaft, wherein the angle between the axis of the extension part and the centerline of the V-groove is less than or equal to 90°.

5. The automatic return device based on a cam mechanism according to claim 1, characterized in that, The slider mechanism (3) includes a push rod (31), a bearing connecting rod (32) and a bearing (33). One end of the push rod (31) is rotatably connected to the base plate (1), and the other end is fixedly connected to the bearing connecting rod (32). The bearing (33) is connected to the bearing connecting rod (32).

6. The automatic return device based on a cam mechanism according to claim 5, characterized in that, The reset mechanism (4) includes a tension spring (41) and a bolt (42). One end of the tension spring (41) is connected to the bearing connecting rod (32), and the other end is connected to the pump body by the bolt (42).

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