Oil cylinder with fixed return stroke

Abstract

The oil cylinder with the fixed return stroke comprises an oil cylinder body with the hollow interior, a piston and a sealing piece are arranged in a cavity of the oil cylinder body, the outer wall of the piston is sleeved with the sealing piece, the sealing piece is in seamless contact with the inner wall of the oil cylinder body, and a friction piece and a return spring are arranged in the cavity of the oil cylinder body. The friction piece is in seamless contact with the inner wall of the oil cylinder body, the return spring is located between the friction piece and the piston, and the friction force between the friction piece and the inner wall of the oil cylinder body is larger than the elastic force of the return spring. The problem that the return stroke of an oil cylinder piston is fixed is solved, the working stroke of the oil cylinder piston is kept within a relatively fixed numerical value, the operation working stroke is kept within a relatively small range, the oil cylinder piston can be separated cleanly under the forced action of a spring during separation, dragging and energy waste are avoided, and the problem of automatic compensation of a brake shoe can be solved. And the structure is simple, the cost is very low, and the reliability is very high. Therefore, the unilateral double-inclined-plane disc brake can better serve the society.

Description

Technical Field

[0001] The invention relates to the field of brakes for traffic and transport machinery, in particular to an oil cylinder with a fixed return stroke. Background Art

[0002] In traditional oil cylinders, the piston return stroke is a large range. In some fields, the return stroke needs to be relatively consistent to meet its use needs. For example, the return stroke of the commonly used hydraulic disc brake master cylinder (caliper) is a relatively fixed value, generally around 0.15-0.3, and its return force is generated by the sealing rubber ring. It cannot be achieved if the return amount is larger. Especially when applied to the Chinese patent with patent number 201310534271.0 and patent name of single-sided double-bevel disc brake, the structure of the traditional oil cylinder piston obviously cannot meet the needs of the single-sided double-bevel disc brake, because this brake needs a larger working stroke, such as about 0.4-2 mm, and the return stroke also needs a fixed amount, such as 0.4-2 mm. The structure of returning with a rubber sealing ring obviously cannot meet the needs. The present invention is invented to solve the problem that a single-sided double-bevel disc brake uses hydraulic drive (energy transmission) to well generate a relatively fixed gap between the brake disc and the brake shoe, thereby solving the problem of brake drag and a large increase in fuel consumption.

[0003] When the brake shoe of the above patented product is worn during braking, the working stroke of the piston increases. In order to separate completely and cleanly, if the return stroke of the piston in the oil cylinder is variable, it cannot meet the needs. For example, since the working stroke and return stroke of the piston increase from 1 mm to 1.1 mm after the brake shoe is worn, and the piston return stroke is also 1.1 mm after the brake is released, if the shoe is further worn, the working stroke of the piston must be increased, so the working flow required by the oil cylinder must be increased, and the stroke of the operating handle or pedal must be increased. After they are increased to a certain value, the brake cannot work normally. In order to solve the problem that the oil cylinder can move forward a little more after the brake shoe is worn, and no longer return to the starting position when returning, the return stroke is a little less than the forward stroke during work, the return stroke is always a relatively fixed value, and the forward stroke during work can be a little larger than the return stroke. In this way, the brake can be separated cleanly after the brake shoe is worn, and can be automatically compensated without increasing the operating stroke, so that it can work normally. Without this structure, the single-sided double-bevel disc brake can hardly work normally when using hydraulic energy transmission. The caliper piston of the current hydraulic disc brake has a very small working stroke, generally only 0.1-0.3 mm. They use the elastic return of the rubber seal ring, and the return amount of each rubber ring is basically the same each time. After the brake shoe is worn, the piston advances a small amount more, and when returning, the piston returns to this fixed amount. At this time, the piston return amount is a little smaller than the forward amount, which solves the problem of not increasing the operating stroke and compensating for the wear of the brake shoe. However, this method cannot be used directly on a single-sided double-bevel disc brake, because the required piston return amount is much larger than the return amount of the current hydraulic disc brake caliper piston (about 0.3). This structure cannot meet the needs. Summary of the invention

[0004] The purpose of the present invention is to overcome the problems raised in the above-mentioned background technology and to provide a cylinder with a fixed return stroke, which can keep the working stroke within a relatively fixed value and the operating working stroke within a relatively small range. When separating, it can be separated cleanly under the forced action of the spring without dragging or wasting energy, and can also solve the problem of automatic compensation of the brake shoe.

[0005] The purpose of the present invention is mainly achieved through the following technical solutions: A cylinder with a fixed return stroke comprises a hollow cylinder body, a piston and a seal are arranged in the cavity of the cylinder body, and the seal is sleeved on the outer wall of the piston and is in seamless contact with the inner wall of the cylinder body, a friction piece and a return spring are arranged in the cavity of the cylinder body, the friction piece is in seamless contact with the inner wall of the cylinder body, the return spring is located between the friction piece and the piston, and the friction force between the friction piece and the inner wall of the cylinder body is greater than the elastic force of the return spring. The caliper piston of the hydraulic disc brake is currently very small because its working stroke is generally only 0.1-0.3 mm, and they use the elastic return of the rubber seal ring, and the return amount of each rubber ring is basically the same each time, and the piston will move forward a small amount more after the brake shoe is worn, and the piston will still return to the fixed amount when returning, and the piston return amount is a little smaller than the forward amount, so that the operating stroke is not increased, and the problem of compensation for the wear of the brake shoe is solved. However, this method cannot be directly applied to our oil cylinder, because the required piston return amount is much larger than the return amount of the current hydraulic disc brake caliper piston (about 0.3). This structure cannot meet the needs. In order to solve the above problems, this scheme designs an oil cylinder with a fixed return stroke, including an internal hollow oil cylinder body, a piston and a seal are arranged in the cavity of the oil cylinder body, and the seal is sleeved on the outer wall of the piston and seamlessly contacts with the inner wall of the oil cylinder body. The oil cylinder body, the piston and the seal are all existing components, and the connection relationship and position relationship adopted are all existing structures. This scheme is to arrange a friction member and a return spring in the cavity of the oil cylinder body, the friction member is seamlessly in contact with the inner wall of the oil cylinder body, the return spring is located between the friction member and the piston, and the friction force between the friction member and the inner wall of the oil cylinder body is greater than the elastic force of the return spring. In this way, a very simple method is used to solve the problem of fixing the return stroke of the oil cylinder piston, so that its working stroke is kept within a relatively fixed value, and the operating working stroke is kept within a relatively small range. When separating, it can be separated cleanly under the forced action of the spring, without dragging and wasting energy, and the problem of automatic compensation of the brake shoe can be solved. It also has a simple structure, very low cost, and very high reliability.

[0006] The return spring can be a coil spring or a disc spring, but the disc spring is better because it has a small axial size, a large elastic force, and a small working stroke. The return force should be greater than the need for the piston to return. As long as the friction ring can generate enough friction with the cylinder wall and the friction force is greater than the return force of the return spring, any structure is acceptable. An adjustment part, such as a nut, can also be installed before it is damaged by friction.

[0007] Furthermore, an oil inlet pipe is provided on the oil cylinder body, and the oil inlet pipe is communicated with the cavity of the oil cylinder body. The oil inlet pipe is used to input hydraulic oil into the cavity of the oil cylinder body.

[0008] Furthermore, an exhaust through hole is provided on the oil cylinder body, and the exhaust through hole is connected to the cavity of the oil cylinder body, and an exhaust screw is provided in the exhaust through hole. The exhaust through hole is provided to exhaust the gas in the oil cylinder body, and after exhausting, the exhaust through hole is sealed by the exhaust screw to ensure the sealing of the cavity, so that the pressure reaches the required level.

[0009] Furthermore, the piston rod of the piston passes through the friction member and can move along its own axis direction, so as not to affect the normal reciprocating motion of the piston, and the piston rod can pass through the friction member and reciprocate as required.

[0010] In summary, the present invention has the following beneficial effects compared with the prior art: The present invention solves the problem of fixed return stroke of oil cylinder piston, keeps its working stroke within a relatively fixed value, keeps the operating working stroke within a relatively small range, and can separate cleanly under the forced action of spring when separating, without dragging and wasting energy, and can solve the problem of automatic compensation of brake shoe. It also has simple structure, very low cost and very high reliability. Thus, the single-sided double-bevel disc brake can better serve the society and reduce the harm of traffic accidents to people and society. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings: Figure 1 It is a structural schematic diagram of the present invention.

[0012] Figure 2 This is the front view of the butterfly spring.

[0013] Figure 3 This is a side view of the butterfly spring.

[0014] Figure 4 This is the front view of the friction part.

[0015] Figure 5 It is a side view of the friction part.

[0016] Figure 6 A schematic structural diagram of another embodiment.

[0017] The names corresponding to the reference numerals in the accompanying drawings are: 1-Cylinder body, 2-Friction part, 3-Return spring, 4-Piston, 5-Exhaust screw, 6-Oil inlet pipe, 7-Seal, 8-Mounting sleeve, 9-Coil spring. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0020] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention. Embodiment 1:

[0021] like Figures 1 to 5 As shown, a cylinder with a fixed return stroke in this embodiment includes a hollow cylinder body 1, a piston 4 and a seal 7 are arranged in the cavity of the cylinder body 1, and the seal 7 is sleeved on the outer wall of the piston 4 and is in seamless contact with the inner wall of the cylinder body 1. In order to facilitate the injection of hydraulic oil into the cylinder body 1, an oil inlet pipe 6 is arranged on the cylinder body 1, and the oil inlet pipe 6 is connected to the cavity of the cylinder body 1. In order to discharge the gas, an exhaust through hole is arranged on the cylinder body 1, and the exhaust through hole is connected to the cavity of the cylinder body 1. An exhaust screw 5 is arranged in the exhaust through hole. After exhausting the gas, the exhaust screw 5 is tightened to seal the exhaust through hole, so that the cylinder body 1 is in a sealed state. The piston rod of the piston 4 passes through the friction member 2 and can move along its own axis. In this way, the normal reciprocating motion of the piston will not be affected, and the piston rod can pass through the friction member 2 and reciprocate as needed. A friction member 2 and a return spring 3 are arranged in the cavity of the cylinder body 1. The friction member 2 is in seamless contact with the inner wall of the cylinder body 1. The return spring 3 is located between the friction member 2 and the piston 4. In this embodiment, the return spring 3 adopts a disc spring, and the friction force between the friction member 2 and the inner wall of the cylinder body 1 is greater than the elastic force of the return spring 3.

[0022] When the pressure oil enters the oil cylinder body 1 from the oil inlet pipe 6, the pressure oil pushes the piston 4 to move to the left. In addition to moving, the piston 4 also compresses the return spring 3. At this time, since the friction force generated between the friction member 2 and the oil cylinder body 1 is greater than the pressure generated by the return spring 3, and the working stroke of the piston 4 is too small due to the wear of the brake shoe, the pressure of the friction member 2 is only acted on by the return spring 3. Since the friction force generated by the friction member 2 and the oil cylinder body 1 is greater than the force of the return spring 3 acting on it, the friction member 2 does not move to the left. When the operating force disappears, the piston 4 moves to the right under the action of the return spring 3 by a distance that is basically the same as the working stroke (moving to the left), and it completes a normal working process. Its automatic compensation works like this. Since the compression amount (working stroke) L of the return spring 3 is a fixed value, when the brake shoe is worn, the working stroke of the piston 4 will increase by a very small amount, such as 0.1 mm. At this time, the working stroke of the piston 4 is L+0.1. This 0.1 is the working stroke of the piston increased by the wear of the shoe. If the piston 4 returns according to its working stroke every time, the brake shoe can only increase the working stroke of the piston to compensate after the wear, which will increase the operating stroke a lot, and finally it will not work normally. Our invention is that when the brake shoe is worn, the operating stroke increases by a very small amount, and the oil is used for automatic compensation. The specific working principle is as follows. When the brake shoe is worn, the working stroke of the piston 4 will increase by a very small amount, such as 0.1 mm. At this time, the working stroke of the piston 4 is L+0.1, and the 0.1 is the working stroke of the piston increased by the wear of the shoe. Since the limit stroke of the return spring 3 is L, the return spring 3 will press on the friction member 2 with the extra 0.1 stroke. Since the pressure generated by the piston 4 under the action of the hydraulic pressure is much greater than the friction between the friction member 2 and the cylinder body 1, the friction member 2 will move to the left by 0.1 mm. When the pressure disappears, due to The return force of the return spring 3 is smaller than the friction force between the friction member 2 and the oil cylinder body 1. The friction member 2 does not move. The return spring 3 only allows the piston 4 to return to the right by a stroke of L. The piston 4 no longer returns to the starting point of this work, but returns to a position 0.1 to the left of the starting point. In this way, the piston 4 still basically travels an amount of L in the next working stroke, and the working stroke will not increase much. In this way, an automatic compensation stroke is completed. At this time, the distance between the oil cylinder body 1 and the piston 4 increases, and the hydraulic oil flows into the oil cylinder from the oil reservoir a little more, so that automatic compensation is performed. After each braking, the return of the piston 4 is a fixed value, and it is forced to return by a spring, so that there is enough clearance between the brake shoe and the brake disc without dragging, which also solves the requirement that the operating stroke does not increase a lot. Embodiment 2:

[0023] like Figure 6As shown, this embodiment is another structure, that is, the return spring adopts a coil spring 9, and is arranged in the cavity of the oil cylinder body 1 by using a mounting sleeve 8. The mounting sleeve 8 is concave along the axial direction to form an annular mounting groove, the coil spring 9 is sleeved in the mounting groove, the friction member 2 is also sleeved in the mounting groove, and the outer wall of the friction member 2 is seamlessly connected with the inner wall of the oil cylinder body 1, and the friction force between the friction member 2 and the inner wall of the oil cylinder body 1 is still kept greater than the elastic force of the coil spring 9. When the piston 4 moves, it can act on the mounting sleeve 8, so that the mounting sleeve 8 has a tendency to move. The other working principles are the same as those of the embodiment 1. Its working stroke is kept within a relatively fixed value, and the operating working stroke is kept within a relatively small range. When separated, it can be separated cleanly under the forced action of the spring, without dragging and wasting energy, and the problem of automatic compensation of the brake shoe can be solved. And it has a simple structure, very low cost, and very high reliability.

[0024] The contents not described in detail in this specification belong to the prior art known to the professional and technical personnel in this field. The standard parts used in the present invention can be purchased from the market, and the special-shaped parts can be customized according to the description and the drawings. The specific connection methods of each part adopt the conventional means such as mature bolts, rivets, welding, etc. in the prior art. The machinery, parts and equipment all adopt the conventional models in the prior art, and the circuit connection adopts the conventional connection method in the prior art, which will not be described in detail here.

[0025] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A cylinder with a fixed return stroke, comprising a hollow cylinder body (1), a piston (4) and a sealing member (7) being arranged in the cavity of the cylinder body (1), and the sealing member (7) being sleeved on the outer wall of the piston (4) and in seamless contact with the inner wall of the cylinder body (1), characterized in that: A friction member (2) and a return spring (3) are arranged in the cavity of the oil cylinder body (1); the friction member (2) is in seamless contact with the inner wall of the oil cylinder body (1); the return spring (3) is located between the friction member (2) and the piston (4); and the friction force between the friction member (2) and the inner wall of the oil cylinder body (1) is greater than the elastic force of the return spring (3).

2. The oil cylinder with fixed return stroke according to claim 1, characterized in that: The oil cylinder body (1) is provided with an oil inlet pipe (6), and the oil inlet pipe (6) is in communication with the cavity of the oil cylinder body (1).

3. The oil cylinder with fixed return stroke according to claim 1, characterized in that: The oil cylinder body (1) is provided with an exhaust through hole, the exhaust through hole is in communication with the cavity of the oil cylinder body (1), and an exhaust screw (5) is provided in the exhaust through hole.

4. The oil cylinder with fixed return stroke according to claim 1, characterized in that: The piston rod of the piston (4) passes through the friction member (2) and is capable of moving along its own axial direction.

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