Piston push rod directly formed by powder metallurgy process and pedal travel simulator

Abstract

The piston push rod directly formed through the powder metallurgy technology comprises a push rod body, the push rod body comprises a rotating body, a vertical rod and a disc, the vertical rod is arranged at the bottom of the rotating body, the disc is arranged at the bottom end of the vertical rod, the rotating body and the vertical rod form an integrated structure, and a bearing face is arranged at the top end of the vertical rod. According to the formed piston push rod, due to the fact that the rotating body and the vertical rod do not need to be arranged in a tangent mode, turning does not need to be conducted on the rotating body when the push rod body is produced, the piston push rod can be directly formed through powder metallurgy when being produced through the first transition part, the second transition part and the third transition part which are arranged on the disc, and production efficiency is improved. On the other hand, the utility model further provides the pedal travel simulator provided with the piston push rod, the pedal travel simulator is used for simulating an automobile pedal, and the using effect is guaranteed.

Description

Technical Field

[0001] The utility model belongs to the technical field of pedal simulators, in particular to a piston push rod and a pedal stroke simulator directly formed by a powder metallurgy process. Background Art

[0002] The pedal travel simulator is an important component in the automobile braking system. Its main function is to convert the driver's action of stepping on the brake pedal into an electrical signal and transmit it to the vehicle's brake control unit to achieve braking control. The pedal travel simulator is usually composed of sensors, springs and other components. The quality of its performance directly affects the driver's feeling of braking and the effect of vehicle braking. For example, a good pedal travel simulator can provide linear brake pedal feedback, allowing the driver to control the braking force more accurately.

[0003] The piston push rod is one of the components of the pedal stroke simulator, and its function is to squeeze the butterfly spring group through the piston. In the prior art, when the piston push rod is produced, it first needs to be cold headed, and then the surface of the piston push rod is not smooth enough after cold headed. In order to improve the smoothness of the piston push rod, it is usually necessary to turn the edge of the piston push rod through a turning equipment and grind it with a grinding device. The manufacturing procedure is cumbersome, the processing cost is high, and the processing precision requirements are high, which leads to low production efficiency. Utility Model Content

[0004] The purpose of this section is to summarize some aspects of the embodiments of the utility model and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and utility model name of this application to avoid blurring the purpose of this section, specification abstract and utility model name, and such simplifications or omissions cannot be used to limit the scope of the utility model.

[0005] In order to solve the problem of complicated piston push rod process in the prior art mentioned in the above background technology, the utility model adopts the following technical solution.

[0006] A piston push rod directly formed by a powder metallurgy process includes a push rod body directly formed in one piece by a powder metallurgy process, the push rod body includes a rotating body, a vertical rod and a disk, the top of the vertical rod is integrally formed with the rotating body, and the bottom of the vertical rod is integrally formed with the disk, the radius of the vertical rod is greater than the radius of the rotating body so that a bearing surface is formed at the top of the vertical rod, and the axis of the rotating body coincides with the axis of the vertical rod.

[0007] Preferably, the disc is composed of a first step and a second step, the edge of the first step is provided with a first transition portion, the surface edge of the second step is provided with a second transition portion, and the bottom edge of the second step is provided with a third transition portion.

[0008] Preferably, the surfaces of the first step and the second step are inclined surfaces, and the angle between the inclined surfaces and the horizontal plane is greater than 100°.

[0009] Preferably, the rotating body is any one of a hemisphere, a cone, a frustum and a cylinder.

[0010] Preferably, a plurality of grooves are formed at the bottom of the disk, and the plurality of grooves are evenly distributed in a ring shape about the central axis of the disk. The disk is coaxially arranged with the vertical rod, and transition fillets are formed at the edges of the grooves.

[0011] On the other hand, the utility model provides a pedal stroke simulator equipped with the piston push rod, which adopts the following technical solution.

[0012] A pedal stroke simulator comprises a bottom cylinder, a sleeve is built in the bottom cylinder, and a top cylinder is connected to the top of the bottom cylinder, a cavity is formed between the bottom cylinder and the top cylinder, a disc spring group is built in the sleeve, a gasket is connected to the top of the disc spring group, and the above-mentioned piston push rod is assembled on the gasket, and a sealing assembly is sealingly and slidably connected in the top cylinder, the piston push rod is located below the sealing assembly, a spring is sleeved on the vertical rod in the piston push rod, one end of the spring is connected to the sealing assembly, and the other end abuts against the disc of the piston push rod.

[0013] Preferably, the sealing assembly includes a piston, which divides the inner cavity of the top cylinder into two chambers, the piston push rod is located in the chamber below the piston, and the bottom of the piston is located above the piston push rod and a travel cavity is provided.

[0014] Preferably, the outer side of the piston fits with the inner wall of the top cylinder, and a cavity for accommodating hydraulic oil is formed between the top cylinder and the top of the piston. The increased pressure in the cavity can drive the piston push rod to move downward. An oil delivery channel is provided at the top of the top cylinder, and the oil delivery channel is used to introduce hydraulic oil into the top cylinder. When the hydraulic oil enters the top cylinder, the pressure in the cavity above the top cylinder and the top of the piston is increased.

[0015] Preferably, an annular groove is formed on the outer side of the piston, and a sealing ring is arranged inside the annular groove. The sealing ring extends to the outer side of the annular groove and is tightly pressed against the inner wall of the top cylinder to seal the top cylinder.

[0016] Preferably, the sealing ring is composed of an annular portion and an abutting portion, the annular portion is embedded in the annular groove of the piston side wall, and the annular portion and the abutting portion are integrally formed, the abutting portion is inclined, and the abutting portion abuts against the inner wall of the top tube.

[0017] Compared with the prior art, the beneficial effects of the utility model are:

[0018] 1. The piston push rod in the utility model is directly formed by powder metallurgy process during the production and processing. The formed piston push rod includes a vertical rod and a rotating body. The inner diameter of the vertical rod is larger than the inner diameter of the rotating body, so that the top of the vertical rod forms a bearing surface, avoiding the use of turning process for the piston push rod during the forming process in the prior art, thereby improving the production efficiency of the piston push rod and ensuring the production quality of the piston push rod. In addition, the piston push rod forms a disc during forming, and the disc includes a first step and a second step. The surfaces of the first step and the second step are inclined surfaces with a slope greater than 100°. The surface edges of the first step and the second step respectively form a first transition portion and a second transition portion, and the lower surface edge of the second step forms a third transition portion, so that the surface of the formed piston push rod is smooth and the forming quality is good.

[0019] 2. The piston push rod in the utility model is assembled in a pedal stroke simulator, a disc spring group is assembled in the pedal stroke simulator, and a spring is arranged on the piston push rod, and a piston is arranged above the piston push rod. Hydraulic oil enters the pedal stroke simulator, thereby increasing the pressure of the pedal stroke simulator to drive the piston to move, thereby driving the piston push rod to move. When the hydraulic oil continuously enters, the piston resists the elastic force of the spring and further drives the piston push rod to move, thereby resisting the elastic force of the disc spring group. Therefore, the condition of the automobile pedal can be simulated, and the use effect is guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a front view of a piston push rod in the prior art;

[0021] Figure 2 It is a schematic diagram of the bottom structure of the piston push rod in the prior art;

[0022] Figure 3 This is a cross-sectional view of the pedal stroke simulator in the utility model;

[0023] Figure 4 This is a schematic diagram of the assembly structure of the piston push rod and the disc spring assembly in the utility model;

[0024] Figure 5 It is a three-dimensional structural schematic diagram of the piston push rod in the utility model;

[0025] Figure 6 This is a schematic diagram of the top structure of the piston push rod in the utility model;

[0026] Figure 7 This is a schematic diagram of the structure of the bottom of the piston push rod in the utility model;

[0027] Figure 8 It is a bottom view of the piston push rod in the utility model;

[0028] Fig. 9It is a top view of the piston push rod in the utility model;

[0029] Fig.10 It is a three-dimensional structural schematic diagram of the sealing ring in the utility model.

[0030] The corresponding relationship between the illustrations and component names in the figure is as follows:

[0031] 1. Push rod body; 101. Rotating body; 102. Vertical rod; 102a. Bearing surface; 103. Disc; 103a. First transition part; 103b. Second transition part; 103c. Third transition part; 104. Groove; 104a. Transition fillet; 2. Spring; 3. Piston; 4. Gasket; 5. Disc spring assembly; 6. Sleeve; 7. Top cylinder; 8. Bottom cylinder; 9. Sealing ring; 901. Annular part; 902. Abutment part; 10. Hydraulic oil hole. DETAILED DESCRIPTION

[0032] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0033] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0034] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments. The present invention provides the following embodiments.

[0035] like Figures 1-2 As shown, it is a structural schematic diagram of a piston push rod in the prior art. The piston push rod in the prior art includes a vertical rod and a disc, wherein a rotating body is provided at the top of the vertical rod, and the rotating body and the vertical rod are integrally formed and tangent to each other. The piston push rod in the prior art adopts a cold heading process to form the piston push rod during processing, but it is necessary to ensure that the rotating body is tangent to the vertical rod. Therefore, the piston push rod in the prior art needs to be turned by a turning process during processing to ensure that the rotating body and the vertical rod are tangent to each other. However, the processing technology is complicated and the production efficiency of the piston push rod is low. In order to solve this problem, the utility model adopts the following embodiment.

[0036] like Figure 3As shown, it is a schematic diagram of the structure of the pedal stroke simulator in this embodiment. The pedal stroke simulator in this embodiment is built with a piston push rod. The piston push rod in this embodiment is directly formed by powder metallurgy process, which avoids the need for cold heading and cutting and other processes when processing the piston push rod in the prior art. The piston push rod in this embodiment is directly formed by powder metallurgy, which improves the production efficiency of the piston push rod. Figures 4 to 9 As shown, the piston push rod includes a push rod body 1, and the push rod body 1 includes a rotating body 101, a vertical rod 102 and a disk 103. The top of the vertical rod 102 is integrally formed with the rotating body 101, and the bottom of the vertical rod 102 is integrally formed with the disk 103. The vertical rod 102, the disk 103 and the rotating body 101 are an integrated structure, which is integrally formed by powder metallurgy. The central axis of the vertical rod 102 coincides with the central axis of the rotating body 101. In this embodiment, the rotating body 101 is a hemisphere. It is worth noting that in this technical solution, the structure of the rotating body 101 is not limited to a hemisphere, and can also be any one of a cone, a truncated cone and a cylinder, such as Figure 6 As shown, in this embodiment, the inner diameter of the vertical rod 102 is larger than the inner diameter of the rotating body 101, so that a bearing surface 102a is formed at the top of the vertical rod 102. During powder metallurgy forming, the vertical rod 102 and the rotating body 101 are integrally formed, and there is no need for the rotating body 101 and the vertical rod 102 to be tangent. Therefore, the piston push rod in this embodiment avoids the need to use a turning process to make the rotating body 101 and the vertical rod 102 tangent in the prior art. The rotating body 101 and the vertical rod 102 in this embodiment do not need to be formed in a tangent manner, so there is no need to use a turning process for processing, which reduces the processing complexity of the piston push rod and improves the processing efficiency of the piston push rod.

[0037] In addition, in this embodiment, Figure 5 as well as Fig. 9 As shown, when the piston push rod is formed by powder metallurgy, the disc 103 is composed of a first step and a second step, and the surfaces of the first step and the second step are inclined surfaces, and the angle between the inclined surface and the horizontal plane is greater than 100°, that is, the slope angle of the first step and the second step is greater than 100°. In this embodiment, the edge of the first step is provided with a first transition portion 103a, and the surface edge of the second step is provided with a second transition portion 103b, and, as shown in FIG. Figure 7 As shown, the bottom edge of the second step is provided with a third transition portion 103c, and the first transition portion 103a, the second transition portion 103b and the third transition portion 103c are provided on the disc 103, so that the edge of the disc is smooth during production, thereby ensuring the molding quality of the piston push rod.

[0038] In addition, if Figure 7 as well as Figure 8As shown, in the present embodiment, a plurality of grooves 104 are provided at the bottom of the disk 103, and the plurality of grooves 104 are evenly distributed in a ring shape about the central axis of the disk 103. The disk 103 is coaxially arranged with the vertical rod 102, and the edge of the groove 104 is provided with a transition fillet 104a. The setting of the groove 104 facilitates the clamping connection between the push rod body 1 and the internal components of the pedal stroke simulator. At the same time, the edge of the groove 104 is provided with a transition fillet 104a, so that the push rod body 1 can be directly formed by powder metallurgy during production without turning processing, thereby reducing costs and having high manufacturing precision.

[0039] The piston push rod in this embodiment is assembled in a pedal stroke simulator. In order to better illustrate the structure of the pedal stroke simulator including the piston push rod in this embodiment, a technical solution of the pedal stroke simulator is given in this embodiment.

[0040] like Figure 3 As shown, it is a schematic diagram of the structure of the pedal stroke simulator in this embodiment. The pedal stroke simulator in this embodiment includes a bottom cylinder 8, a sleeve 6 is built in the bottom cylinder 8, and a top cylinder 7 is connected to the top of the bottom cylinder 8, and a cavity is formed between the bottom cylinder 8 and the top cylinder 7. In this embodiment, a disc spring group 5 is built in the sleeve 6, a gasket 4 is connected to the top of the disc spring group 5, and the gasket 4 is equipped with the above-mentioned piston push rod. Specifically, a protrusion is provided on the gasket 4, and the protrusion is clamped in the groove 104 of the disc 103 on the piston push rod, which ensures the stability between the gasket 4 and the piston push rod, and the piston 3 is sealingly and slidably connected in the top cylinder 7, as shown Figure 3 As shown, in this embodiment, a travel cavity is provided at the bottom of the piston 3 above the piston push rod, and a spring 2 is sleeved on the vertical rod 102 in the piston push rod. One end of the spring 2 is connected to the piston 3, and the other end abuts against the disc 103 of the piston push rod.

[0041] In the present embodiment, the sealing assembly formed by the piston 3 is used to seal the inner cavity of the top tube 7 to form two chambers. When the pressure in the chamber at the top of the sealing assembly increases, the sealing assembly can be driven to move downward in the top tube 7 and then the piston push rod in the present embodiment can be pushed to move. It should also be noted that, in the present embodiment, the piston 3 is used to seal the inner cavity of the top tube 7, and other sealing assemblies can be used in the present embodiment as long as they can play a sealing role.

[0042] In this embodiment, the sealing component is a piston 3, the outer side of the piston 3 fits with the inner wall of the top tube 7, the outer side of the disc spring group 5 fits with the inner wall of the sleeve 6, and the top tube 7 and the bottom tube 8 are threadedly connected.

[0043] like Figure 3As shown, in the pedal stroke simulator in this embodiment, an oil delivery channel is provided on the top cylinder 7, and the oil delivery channel is connected with the automobile brake cylinder. When the automobile brakes, the hydraulic oil generated by the operation of the automobile brake cylinder enters into the pedal stroke simulator in this embodiment through the oil delivery channel. In this embodiment, the oil delivery channel is a hydraulic oil hole 10, and the hydraulic oil hole 10 is located at the top of the top cylinder 7. The hydraulic oil hole 10 runs through the top of the top cylinder 7. When the automobile brakes, the hydraulic oil enters into the pedal stroke simulator through the hydraulic oil hole 10, thereby pushing the piston 3 to move downward to resist the elastic force of the compression spring 2. After the hydraulic oil continuously enters into the pedal stroke simulator, after resisting the elastic force of the compression spring 2, it further drives the piston push rod to move, so that the piston push rod resists the elastic force of the disc spring group 5 in the pedal stroke simulator, thereby achieving the purpose of simulating the automobile pedal.

[0044] In addition, if Figure 3 As shown, in order to further improve the sealing effect of the piston 3 on the top cylinder 7, in the present embodiment, an annular groove is opened on the outer side of the piston 3, and a sealing ring 9 is arranged inside the annular groove, and the sealing ring 9 is located in the annular groove of the piston 3 and abuts against the inner wall of the top cylinder 7, so that the sealing effect of the piston 3 on the top cylinder 7 is better. When the hydraulic oil enters the top cylinder 7 and is located above the piston 3, the pressure of the cavity above the piston 3 in the top cylinder 7 increases, thereby driving the piston 3 to move; in the present embodiment, the elasticity of the sealing ring 9 makes the sealing ring 9 fit with the inner wall of the top cylinder 7, thereby ensuring the sealing effect. Through the coordinated use of the top cylinder 7 and the bottom cylinder 8, the internal components of the pedal stroke simulator can be protected. The setting of the sealing ring 9 can seal the cavity in the top cylinder 7 to prevent the liquid inside the cavity from entering the cavity below the piston 3.

[0045] like Fig.10 As shown, in this embodiment, the sealing ring 9 is composed of an annular portion 901 and an abutting portion 902. The annular portion 901 is embedded in the annular groove of the side wall of the piston 3, and the annular portion 901 and the abutting portion 902 are integrally formed and made of elastic material. In this embodiment, the abutting portion 902 is inclined, and the abutting portion 902 abuts against the inner wall of the top tube 7. The sealing effect of the sealing ring 9 is guaranteed by the abutting portion 902 tightly abutting against the inner wall of the top tube 7, so that the hydraulic oil can increase the pressure in the cavity after entering the cavity at the top of the piston 3 to drive the piston 3 to move.

[0046] The piston push rod in this embodiment is directly formed by powder metallurgy during production and processing. The formed piston push rod includes a rotating body 101 and a vertical rod 102. The rotating body 101 and the vertical rod 102 do not need to be tangent to each other, thereby avoiding the turning process. The piston push rod in this embodiment takes about 1.5 seconds to form by powder metallurgy, while the piston push rod produced by the prior art takes about 1 second in the cold heading stage, but takes about 60 seconds in the turning stage. Therefore, when the piston push rod is formed by powder metallurgy in this embodiment, no turning process is required, which greatly reduces the processing time and improves the production efficiency. The piston push rod formed by powder metallurgy in this embodiment also includes a disc 103 A first step and a second step are provided on the disk 103, a first transition portion 103a is provided on the edge of the first step, a second transition portion 103b is provided on the surface edge of the second step, and a third transition portion 103c is provided on the lower surface edge of the second step, so that the edge of the disk is smooth during production and no grinding is required. In addition, a groove 104 is provided on the lower surface of the disk 103 to facilitate the clamping of the push rod body 1 with the internal components of the pedal stroke simulator, and at the same time, a transition fillet 104a is provided on the edge of the groove 104, so that the piston push rod can be directly formed by powder metallurgy during production without turning, thereby reducing the complexity of the production process and having high manufacturing precision.

[0047] In addition, in this embodiment, the piston push rod is installed inside the pedal travel simulator when in use, and the hydraulic oil generated when the car brakes can be guided into the pedal travel simulator through the hydraulic oil hole 10. The liquid enters the cavity between the top cylinder 7 and the top of the piston 3 through the hydraulic oil hole 10, thereby increasing the pressure in the pedal travel simulator, thereby driving the piston 3 to move the compression spring 2. The continuous entry of hydraulic oil causes the piston 3 to apply pressure to the piston push rod and then drive the piston push rod to move, further squeezing the disc spring group 5 to achieve the purpose of simulating the car pedal. The setting of the sleeve 6 can ensure the stability of the compression and downward movement of the disc spring group 5. Through the coordinated use of the top cylinder 7 and the bottom cylinder 8, the internal components of the pedal travel simulator can be protected. The setting of the sealing ring 9 can seal the cavity of the top cylinder 7 to prevent the liquid inside the cavity from entering the sleeve 6.

[0048] The above content is a further detailed description of the utility model in combination with specific implementation methods. It cannot be determined that the specific implementation of the utility model is limited to these descriptions. For ordinary technicians in the technical field to which the utility model belongs, without departing from the concept of the utility model, they can also make several simple deductions or substitutions, which should be regarded as belonging to the scope of protection determined by the claims submitted for the utility model.

Claims

1. A piston push rod directly formed by a powder metallurgy process, comprising a push rod body (1) directly formed in one piece by a powder metallurgy process, wherein the push rod body (1) comprises a rotating body (101), a vertical rod (102) and a disc (103), wherein the top of the vertical rod (102) is integrally formed with the rotating body (101), and the bottom of the vertical rod (102) is integrally formed with the disc (103), and wherein: The radius of the vertical rod (102) is greater than the radius of the rotating body (101), so that a bearing surface (102a) is formed at the top end of the vertical rod (102), and the axis of the rotating body (101) coincides with the axis of the vertical rod (102).

2. The piston push rod directly formed by powder metallurgy process according to claim 1 is characterized in that: The disk (103) is composed of a first step and a second step, the edge of the first step is provided with a first transition portion (103a), the surface edge of the second step is provided with a second transition portion (103b), and the bottom edge of the second step is provided with a third transition portion (103c).

3. The piston push rod directly formed by powder metallurgy process according to claim 2 is characterized in that: The surfaces of the first step and the second step are inclined surfaces, and the angle between the inclined surfaces and the horizontal plane is greater than 100°.

4. The piston push rod directly formed by powder metallurgy process according to claim 3 is characterized in that: The rotating body (101) is any one of a hemisphere, a cone, a truncated cone and a cylinder.

5. The piston push rod directly formed by powder metallurgy process according to claim 4, characterized in that: The bottom of the circular disk (103) is provided with a plurality of grooves (104), which are evenly distributed in a ring shape about the central axis of the circular disk (103). The circular disk (103) and the vertical rod (102) are coaxially arranged, and the edges of the grooves (104) are provided with transition fillets (104a).

6. A pedal travel simulator, characterized in that: It includes a bottom cylinder (8), a sleeve (6) is built into the bottom cylinder (8), and a top cylinder (7) is connected to the top of the bottom cylinder (8), a cavity is formed between the bottom cylinder (8) and the top cylinder (7), a disc spring group (5) is built into the sleeve (6), a gasket (4) is connected to the top of the disc spring group (5), and a piston push rod directly formed by the powder metallurgy process as described in any one of claims 1 to 5 is assembled on the gasket (4), and a sealing assembly is sealingly and slidably connected in the top cylinder (7), the piston push rod is located below the sealing assembly, and a spring (2) is sleeved on the vertical rod (102) in the piston push rod, one end of the spring (2) is connected to the sealing assembly, and the other end abuts against the disc (103) of the piston push rod.

7. The pedal stroke simulator according to claim 6, characterized in that: The sealing assembly comprises a piston (3), wherein the piston (3) divides the inner cavity of the top cylinder (7) into two chambers, the piston push rod is located in the chamber below the piston (3), and a travel cavity is provided at the bottom of the piston (3) above the piston push rod.

8. The pedal stroke simulator according to claim 7, characterized in that: The outer side of the piston (3) is in contact with the inner wall of the top cylinder (7), and a cavity for accommodating hydraulic oil is formed between the top cylinder (7) and the top of the piston (3). The increase in pressure in the cavity can drive the piston (3) to move downward. An oil delivery channel is provided at the top of the top cylinder (7). The oil delivery channel is used to introduce hydraulic oil into the top cylinder (7). When the hydraulic oil enters the top cylinder (7), the pressure of the cavity above the top cylinder (7) and the top of the piston (3) is increased.

9. The pedal stroke simulator according to claim 8, characterized in that: The outer side of the piston (3) is provided with an annular groove, and a sealing ring (9) is arranged inside the annular groove. The sealing ring (9) extends to the outer side of the annular groove and is tightly pressed against the inner wall of the top cylinder (7) to seal the top cylinder (7).

10. The pedal stroke simulator according to claim 9, characterized in that: The sealing ring (9) is composed of an annular portion (901) and an abutting portion (902); the annular portion (901) is embedded in the annular groove of the side wall of the piston (3); the annular portion (901) and the abutting portion (902) are integrally formed; the abutting portion (902) is inclined, and the abutting portion (902) abuts against the inner wall of the top tube (7).

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