Expander

Abstract

The utility model provides an expander, and belongs to the technical field of brakes. The problem that after an existing expander is used for a long time, braking reaction force deviates from the center position is solved. The expander comprises a shell, a push rod assembly, a piston and a columnar adjusting bolt, the inner end of the adjusting bolt is located in the shell, the outer end of the adjusting bolt extends out of the shell, an ejection piece is arranged at the outer end of the adjusting bolt, a concave notch is formed in the center of the end portion of the outer end of the adjusting bolt, and the push rod assembly is arranged in the concave notch. The end portion of one end, facing the adjusting bolt, of the ejection piece is provided with a first spherical face, the ejection piece stretches into the notch, a second spherical face attached to the first spherical face is arranged in the notch, and the outer end of the adjusting bolt is further provided with an anti-disengaging part capable of preventing the ejection piece from disengaging from the adjusting bolt. The dilator has the advantage of long service life.

Description

Technical Field

[0001] The utility model belongs to the technical field of brakes and relates to an expander, in particular to an expander for brakes. Background Art

[0002] The brake is a device that has the function of slowing down, stopping or keeping the moving parts in a stopped state. It is a mechanical part that stops or slows down the moving parts in the machine, commonly known as brakes or gates. The expander is an important component of the brake, which is used to withstand the force and push the iron shoe to move to achieve braking.

[0003] For example, the applicant designed a ratchet expander for a wedge-type brake and applied for a Chinese patent, and its application number is: 202022017040.0; the ratchet expander for a wedge-type brake includes a shell, a push rod device, and a piston device. The shell is provided with a channel hole passing through two opposite sides of the shell, and the shell is also provided with a vertical hole vertically passing through the center of the channel hole and the other side of the shell. A ratchet ejector pin is fixed on the shell, and the piston device is provided with two groups. The two groups of piston devices are mirror-symmetrical and can be movably arranged in the channel holes on both sides of the vertical hole, respectively. The push rod device can be movably arranged in the vertical hole. The piston device includes a piston, a ratchet, and an adjusting bolt assembly. The piston can be slidably arranged in the channel hole. One end of the piston is an inclined surface and contacts with the push rod device. The other end of the piston is provided with an inwardly recessed accommodating hole. The adjusting The whole bolt assembly comprises an adjusting bolt, an adjusting nut and an ejection section. One end of the adjusting bolt is provided with a thread and is arranged in the piston accommodating hole, and the other end is fixed to the ejection section. The adjusting nut is threadedly connected with the adjusting bolt and can move in the piston accommodating hole. The ratchet is sleeved on the adjusting bolt and is close to one end of the adjusting bolt extending into the piston accommodating hole. A coupling portion is provided on the side of the adjusting nut and engages with the ratchet teeth of the ratchet. A gap is provided between the end face of the end of the adjusting bolt extending into the piston accommodating hole and the bottom of the accommodating hole. A disc spring is provided in the gap. The outer edge of the disc spring is tightly attached to the side face of the ratchet, and the center of the disc spring is tightly attached to the bottom of the piston accommodating hole. The piston is provided with a long slot hole for accommodating a ratchet ejector pin to pass through. An inwardly recessed arc ejector pin groove is provided on the circumferential surface of the ratchet. The top of the ratchet ejector pin is tightly attached to the bottom of the arc ejector pin groove and can slide along the bottom of the arc ejector pin groove.

[0004] When the wedge brake is working with a ratchet expander, the push rod device moves inward, and the inclined surface on the piston acts on the inner ends of the two pistons at the same time, so that the two pistons move outward, pushing the two adjusting bolt assemblies outward, and the ejection section at the outer end of the adjusting bolt assembly pushes the brake shoe and the friction pair to move, thereby achieving braking.

[0005] However, in the actual braking process, the friction pair is prone to eccentric wear. After long-term braking, the points of action of the reaction force on the adjustment bolt assembly and piston braking in the expander will shift, that is, deviate from their center position, thereby affecting the braking effect and the service life of the expander. Utility Model Content

[0006] The utility model aims at the above problems existing in the prior art and proposes an expander to solve the problem that the braking reaction force of the prior expander deviates from the central position after long-term use.

[0007] The purpose of the utility model can be achieved through the following technical solutions:

[0008] An expander includes a shell, a push rod assembly, a piston and a columnar adjusting bolt, wherein the inner end of the adjusting bolt is located in the shell, the outer end of the adjusting bolt extends out of the shell, and an ejector is provided at the outer end of the adjusting bolt, characterized in that a recessed notch is provided at the center of the outer end of the adjusting bolt, the ejector has a spherical surface 1 facing one end of the adjusting bolt, the ejector extends into the notch and has a spherical surface 2 in the notch that abuts against the spherical surface 1, and the outer end of the adjusting bolt also has an anti-detachment portion that can prevent the ejector from detaching from the adjusting bolt.

[0009] When the expander is in use, the push rod assembly receives the force applied by the cylinder and other driving parts and moves into the housing, pushing the pistons on both sides of the housing to move away from the push rod assembly, thereby pushing the adjusting bolt to move outward, and the ejector at the outer end of the adjusting bolt pushes the brake shoe and the friction pair to move to achieve braking. During this braking process, the ejector and the outer end of the adjusting bolt are abutted against each other through spherical surface 1 and spherical surface 2, both of which are spherical surfaces. When the friction pair is worn eccentrically, the ejector can be deflected relative to the adjusting bolt along the spherical surface 1 and spherical surface 2 during the next braking to adapt to the direction of the force pushing the friction pair, thereby ensuring the friction and braking effect. At the same time, due to the setting of spherical surface 1 and spherical surface 2, the force point of the reaction force on the ejector is always located at the center point of the adjusting bolt, thereby ensuring the service life of the expander.

[0010] In the above expander, the end of the ejector facing the adjusting bolt also has a flat relief plane. The setting of the relief plane makes the ejector not completely abut against the notch of the adjusting bolt, and a gap is left between the two to avoid complete abutment and adsorption, which facilitates assembly and subsequent deflection of the ejector.

[0011] In the above expander, the end of the ejector away from the adjusting bolt has a convex portion protruding outward in a columnar shape, and there is a distance between the outer wall of the convex portion and the outer edge of the ejector, the anti-slip portion is in the shape of a long strip, one end of the anti-slip portion is connected to one side of the outer end of the adjusting bolt, and the other end bypasses the end of the ejector and approaches the other side of the adjusting bolt, and a through hole is formed on the anti-slip portion and the convex portion passes through the through hole. The convex portion of the ejector passes through the through hole to cooperate with the brake shoe and the friction pair, and the distance between the outer wall of the convex portion and the outer edge of the ejector cooperates with the anti-slip portion to prevent the ejector from falling out.

[0012] In the above expander, the anti-dropout portion is located on both sides of the through hole and has a curved portion that bends and protrudes toward the ejection member in an arc shape. The curved portion protrudes toward one side of the ejection member, reducing the gap between the anti-dropout portion and the ejection member, thereby achieving a better anti-dropout effect.

[0013] Compared with the prior art, in the expander, the ejector and the adjusting bolt are matched and abutted by spherical surface 1 and spherical surface 2, so that the ejector can deflect relative to the adjusting bolt along the spherical surface 1 and spherical surface 2 to adapt to the direction of the force pushing the friction pair, thereby ensuring the friction and braking effect. At the same time, due to the setting of spherical surface 1 and spherical surface 2, the force point of the reaction force on the ejector is always located at the center point of the adjusting bolt, thereby ensuring the service life of the expander. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the structure of the expander.

[0015] Figure 2 It is a schematic diagram of the cross-sectional structure of the expander.

[0016] Figure 3 It is a schematic diagram of the structure of the ejector in the expander.

[0017] In the figure, 1, housing; 2, push rod assembly; 3, piston; 4, adjusting bolt assembly; 5, adjusting bolt; 51, recess; 52, spherical surface 2; 53, anti-slip portion; 54, through hole; 55, bent portion; 6, ejector; 61, spherical surface 1; 62, yielding plane; 63, convex portion. DETAILED DESCRIPTION

[0018] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0019] like Figure 1As shown, the expander includes a housing 1, a push rod assembly 2, a piston 3 and an adjusting bolt assembly 4. The housing 1 has openings at the top and both sides and the three openings are internally connected. The push rod assembly 2 is inserted into the opening at the top of the housing 1. The number of the piston 3 and the adjusting bolt assembly 4 are both two and they are respectively arranged in the openings on both sides of the housing 1. Here, the specific composition, positional relationship and connection relationship of the housing 1, the push rod assembly 2 and the adjusting bolt assembly 4 are the same as those in the applicant's prior application in the background technology, and will not be repeated.

[0020] The following is a specific structural description taking the structure of one of the openings on the side of the housing 1 as an example.

[0021] like Figure 2 As shown, the adjusting bolt assembly 4 includes a columnar adjusting bolt 5, the inner end of which is located in the housing 1, the outer end of which extends out of the housing 1, and a columnar ejector 6 is provided at the outer end of the adjusting bolt 5. A recessed notch 51 is provided at the center of the outer end of the adjusting bolt 5, and the ejector 6 has a spherical surface 1 61 facing one end of the adjusting bolt 5 and extends into the notch 51. The bottom wall and the side wall of the notch 51 form a continuous spherical surface, which is a spherical surface 2 52 that abuts against the spherical surface 1 61. Figure 3 As shown, the end of the ejector 6 facing one end of the adjusting bolt 5 also has a flat clearance plane 62, and the clearance plane 62 is exactly located at the center position of the spherical surface 1 61.

[0022] The end of the ejector 6 away from the adjusting bolt 5 has a protruding portion 63 protruding outward in a columnar shape, and there is a gap between the outer wall of the protruding portion 63 and the outer edge of the ejector 6. Here, the end surface of the ejector 6 away from the adjusting bolt 5 has a groove in the shape of a long strip, and the two ends of the groove are connected to the opposite sides of the ejector 6. There are two protruding portions 63, which are symmetrically arranged on both sides of the groove and are adjacent to the groove. The cross-sections of the two protruding portions 63 are both crown-shaped, and the outer side surfaces of the two protruding portions 63 are located on the same cylindrical surface. A roughly circular step surface is formed between the outer walls of the two protruding portions 63 and the outer edge of the ejector 6.

[0023] The outer end of the adjusting bolt 5 also has an anti-slip portion 53 that can prevent the ejector 6 from detaching from the adjusting bolt 5. The anti-slip portion 53 is in the shape of a long strip, one end of the anti-slip portion 53 is connected to one side of the outer end of the adjusting bolt 5, and the other end is bypassed from the end of the ejector 6 and close to the other side of the adjusting bolt 5. The winding direction of the anti-slip portion 53 is the same as the length direction of the groove. A through hole 54 is formed through the anti-slip portion 53, and two protrusions 63 pass through the through hole 54. The anti-slip portion 53 has a curved portion 55 on both sides of the through hole 54, which is curved and protrudes toward the ejector 6 and is in the shape of an arc.

[0024] When the expander is in use, the push rod assembly 2 receives the force applied by the cylinder and other driving parts and moves into the housing 1, pushing the pistons 3 located on both sides of the housing 1 to move away from the push rod assembly 2, thereby pushing the adjusting bolt assembly 4 to move outward, and the ejector 6 at the outer end of the adjusting bolt 5 pushes the brake shoe and the friction pair to move to achieve braking.

[0025] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. An expander, comprising a housing (1), a push rod assembly (2), a piston (3) and a columnar adjusting bolt (5), wherein the inner end of the adjusting bolt (5) is located in the housing (1), the outer end of the adjusting bolt (5) protrudes out of the housing (1), and an ejector (6) is provided at the outer end of the adjusting bolt (5), characterized in that: The outer end of the adjusting bolt (5) has a recessed notch (51) at the center thereof, the ejector (6) has a spherical surface 1 (61) at one end thereof facing the adjusting bolt (5), the ejector (6) extends into the notch (51) and the notch (51) has a spherical surface 2 (52) in contact with the spherical surface 1 (61), and the outer end of the adjusting bolt (5) also has an anti-detachment portion (53) capable of preventing the ejector (6) from detaching from the adjusting bolt (5).

2. The dilator according to claim 1, characterized in that The end of the ejector (6) facing one end of the adjusting bolt (5) also has a flat yielding plane (62).

3. The dilator according to claim 1 or 2, characterized in that: The end of the ejector (6) away from the adjusting bolt (5) has a protrusion (63) protruding outward in a columnar shape, and there is a distance between the outer wall of the protrusion (63) and the outer edge of the ejector (6); the anti-slip portion (53) is in the shape of a long strip, one end of the anti-slip portion (53) is connected to one side of the outer end of the adjusting bolt (5), and the other end bypasses the end of the ejector (6) and approaches the other side of the adjusting bolt (5); a through hole (54) is penetrated through the anti-slip portion (53) and the protrusion (63) passes through the through hole (54).

4. The expander according to claim 3, characterized in that The anti-slip portion (53) is located on both sides of the through hole (54) and has a curved portion (55) that is curved and protrudes in a circular arc shape toward the ejection member (6).

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