JP2016044692A - Mechanical brake operation device for drum brake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mechanical brake operation device for a drum brake showing a high position setting effect for an operation lever by restricting an operation lever rotating toward a cable drawing direction when external force acts against the operation lever during transportation of the drum brake or during connecting work of the brake cable.SOLUTION: This invention relates to a mechanical brake operation device in which when an operation lever 24 is placed at a position where a work for connecting three members of a brake cable 41, the operation lever 24 and a connecting pin 43 can be carried out, it can be held in a bridge part 23a at a first position against the bridge part 23a of a strat 23 and when the operation lever 24 is placed at a position where a work for connecting three members cannot be carried out, a clip 30 for restricting a rotation toward a counter-cable drawing direction at a second position in respect to the bridge part 23a is movably attached to the bridge part 23a of the strat 23, and when the clip 30 is placed at the first position, the operation lever 24 is held at a position where three members can be connected.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a mechanical brake actuator for a drum brake.

A known mechanical brake actuating device used for a drum brake has a plate-like operation lever and opposed pieces connected by a bridge portion, and the operation lever is accommodated in a space between the opposed pieces so as to be rotatable. Pivot struts and pivot pins are the main components.
This mechanical brake actuator is arranged between a pair of brake shoes. By pulling the brake cable connected to the operating lever, the operating lever rotates about the pivotal support with the strut, and the brake lever of the operating lever is engaged. The joint portion and the brake shoe engaging portion of the strut expand in the opposite direction, and the brake shoe is configured to frictionally engage the brake drum.

In the conventional mechanical brake actuator, the struts block the connection hole provided at the free end portion away from the base portion of the operation lever (the pivot support portion for the strut) and the connection hole of the cable end fixed to the tip of the brake cable. It is made to correspond in the position which is not in the anti-cable pulling direction side, and connecting pins are inserted and connected to these both connecting holes.
Thereafter, the brake cable is pulled to position the connecting pin in the space defined by the pair of opposed pieces of struts so that the connecting pin does not fall out of the operation lever.

By attaching a locking member to the strut bridge and positioning the locking member in the first position, the operation lever is allowed to rotate to a position where the connecting pin can be inserted and connected. Patent Document 1 (Japanese Patent Laid-Open No. 2007-71379), or Patent Document 2 discloses an invention that prevents the connecting pin from falling off by limiting the rotation of the operation lever in the anti-cable pulling direction by positioning to the second position. (Japanese Unexamined Patent Application Publication No. 2011-112165).
These inventions are inventions in which the rotation of the operation lever is restricted by a clip-type or flat plate-type stopper that is attached to the strut bridge, and the connecting pin is prevented from falling out of the operation lever. Yes, after the operation of connecting the operating lever and brake cable is completed, the locking lever prevents the connecting pin from falling off even if the operating lever tries to rotate in the anti-cable pulling direction. It has become.

As another structure, Patent Document 3 (Japanese Patent Laid-Open No. 2004-108458) discloses an invention in which a locking member having an elastic piece is attached to a strut of a mechanical brake actuator.
This invention is an invention in which the rotation of the operation lever is limited by a locking member attached to the strut bridging portion, and the protrusion formed on the control lever is not easily deformed by the elastic piece of the locking member. By restricting the rotation of the operation lever in the anti-cable pulling direction by abutting from the direction, the connecting pin is prevented from falling out of the operation lever, and the protrusion formed on the operation lever is elastic of the stopper member. The connecting pin can be inserted into and connected to the connecting hole of the operating lever by restricting the rotation of the operating lever in the cable pulling direction by contacting the piece from the direction opposite to the direction in which the elastic piece is difficult to deform. The structure can be held in position.

The mechanical brake actuator described above has the following problems.
(1) The inventions described in Patent Documents 1 and 2 do not have a function of holding the operating lever at a position where the operation of connecting the brake cable, the operating lever, and the connecting pin can be performed (connecting work possible position). .
For this reason, the operation lever is rotated by the gap provided between the operation lever and the shoe web of the brake shoe, and the connection hole between the cable end and the operation lever is used when connecting the brake cable and the operation lever. And the work of inserting the connecting pins into the two connecting holes are poor and it takes time and effort.
(2) The invention of Patent Document 3 has a function of holding the connection hole of the operation lever at the connection position with the cable end by the projection formed on the operation lever coming into contact with the elastic piece of the locking member. Since the protrusion is in contact with the elastic piece from the direction in which the elastic piece is easily deformed (the direction opposite to the direction in which the elastic piece is difficult to deform), external force is applied during transporting the drum brake or connecting the brake cable. Thus, the projection of the operating lever easily rotates in the cable pulling direction while deforming the elastic piece.
For this reason, if the protrusion of the operating lever passes over the elastic piece of the locking member before the connecting pin is inserted and the operating lever once rotates in the cable pulling direction, the elastic piece moves in the anti-cable pulling direction of the operating lever. In order to limit the rotation, the connection by the connecting pin becomes impossible, and the operation lever is rotated and returned to the connecting position in a state where the elastic piece of the locking member is forcibly elastically deformed, and the connecting work is performed. Work is required.

JP 2007-71379 A JP 2011-112165 A JP 2004-108458 A (FIGS. 7 and 8)

The present invention has been made in view of the above points, and the object of the present invention is to restrict the rotation of the operating lever when inserting the connecting pin and to connect the brake cable and the operating lever. It is an object of the present invention to provide a mechanical brake actuator for a drum brake that can improve performance.
Still another object of the present invention is to restrict the operation lever from rotating in the cable pulling direction even when an external force is applied during transport of the drum brake or connection work of the brake cable. It is an object of the present invention to provide a mechanical brake actuator for a drum brake having a large lever positioning effect.

The present invention includes a strut having a pair of opposed pieces that are engaged with one brake shoe and connected by a bridge portion, and is engaged in the other brake shoe and accommodated in a space between the opposed pieces of the strut. An operation lever pivotally supported, and when the brake cable connected to the free end portion of the operation lever by a connecting pin is pulled, the operation lever and the strut rotate relative to each other so that they are opposite to each other. A mechanical brake actuating device extending to the strut, comprising a clip slidably attached to the strut bridging portion, the clip being positioned in a first position relative to the strut bridging portion The operating lever is connected to the bridging portion or the clutch so that the brake cable connecting hole formed in the free end portion of the operating lever is completely exposed from the space of the strut. The operation lever is allowed to rotate in the anti-cable pulling direction until it comes into contact with the pop, and when the clip is positioned at the second position with respect to the bridging portion of the strut, the brake cable connecting hole is In the mechanical brake actuator in which the operation lever is in contact with the clip and the rotation of the operation lever in the anti-cable pulling direction is restricted so that the entire space is not exposed from the strut space. The operating lever is in contact with the clip so that the brake cable connection hole formed in the free end of the operating lever is exposed from the strut space when the operating lever is positioned. The rotation in the pulling direction is limited.
In the present invention, when the connecting pin is inserted, the rotation of the operation lever in the cable pulling direction and the anti-cable pulling direction can be surely restricted, and the connection workability between the brake cable and the operation lever is improved. .
Further, according to the present invention, in the mechanical brake operating device described above, a stopper capable of contacting the clip is formed on the peripheral end surface of the operation lever, and the stopper contacts the clip when the clip is in the first position. The operation lever is held at a position where the connection work is possible.
Further, the present invention provides the above-described mechanical brake actuator, wherein an engagement portion that abuts and engages with a cable end fixed to an end portion of the brake cable is formed on the peripheral end surface of the free end portion of the operation lever, When the cable end is engaged with the engaging portion of the operation lever and positioned, both connection holes of the cable end and the operation lever are arranged on the same axis.
Further, according to the present invention, in the mechanical brake actuator described above, the clip has a pair of sandwiching pieces for sandwiching the bridging portion of the strut, and is operated by contacting a part of the sandwiching piece with an operation lever. It has the positioning part which restrict | limits the rotation to the anti-cable pulling direction of a lever, It is characterized by the above-mentioned.
Further, according to the present invention, in the above-described mechanical brake actuator, the clip includes a first positioning hole and a second positioning hole that are loosely fitted to a protrusion formed on an outer surface of a strut bridging portion, and the clip The first and second positioning holes are individually fitted into the projecting portions of the struts, and the clip is positioned at different positions with respect to the bridge portion.

The present invention can obtain at least one of the following effects.
(1) Because the rotation of the operating lever before assembling the brake cable can be reliably restricted and the connecting hole of the operating lever can be kept exposed from the opening of the strut space to the side opposite to the cable pulling direction. The workability of connecting the brake cable and the control lever with the connecting pin is improved.
(2) When an external force is applied during transport of the drum brake or brake cable connection, the operation lever is reliably limited in the direction of cable pulling. large.
(3) The cable end fixed to the end of the inner cable constituting the brake cable is brought into contact with and engaged with the engaging portion formed on the peripheral end surface of the free end of the operating lever, so that both the cable end and the operating lever are The connecting holes can be matched.
For this reason, it is not necessary to visually align the connecting holes of the cable end and the operating lever, so that the working time is further reduced.

The top view which shows an example of the drum brake equipped with the mechanical brake actuator concerning Example 1 II-II sectional view of FIG. 1 is an exploded perspective view showing the configuration of a mechanical brake actuator according to Embodiment 1. FIG. FIG. 4 is an operation explanatory view of the mechanical brake operating device according to the first embodiment, in which the clip is positioned at the first position with respect to the strut bridge portion, and the rotation of the operation lever in the cable pulling direction is limited by the clip. The enlarged view showing a state where the connection hole of the free end portion of the operation lever is exposed to the side opposite to the cable pulling direction from the opening of the strut space FIG. 6 is an explanatory diagram of the operation of the mechanical brake actuator according to the first embodiment, in which the clip is located at a second position with respect to the strut bridging portion, and the clip rotates the operating lever in the anti-cable pulling direction. An enlarged view showing a state where the connection hole of the free end portion of the operation lever is overlapped with the opposing piece of the strut, which is restricted. The disassembled perspective view which shows the structure of the mechanical brake actuator concerning Example 2. FIG. FIG. 10 is a diagram that also serves as a structural explanatory diagram and an operational explanatory diagram of a mechanical brake operating device according to a second embodiment, in which the clip is positioned at a first position with respect to the strut bridging portion, and the cable pulling of the operation lever is performed by the clip. An enlarged view showing a state where the rotation in the direction is restricted and the connection hole of the free end portion of the operation lever is exposed to the side opposite to the cable pulling direction from the opening of the space of the strut It is a figure which serves as a structure explanatory drawing and action explanatory drawing of the mechanical brake actuator concerning Example 2, Comprising: A clip is located in a 2nd position with respect to the bridging part of a strut, The anti-cable of an operation lever with the clip Enlarged view showing a state where the pivoting in the pulling direction is restricted and the connecting hole of the free end portion of the operating lever overlaps the opposing piece of the strut FIG. 10 is a diagram that also serves as a structural explanatory diagram and a functional explanatory diagram of a mechanical brake actuator according to a third embodiment, in which a clip is positioned at a first position with respect to a strut bridge, and a cable end of a brake cable is an operation lever. The enlarged view which shows the state contact | abutted to the cable pulling direction side peripheral end surface of the free end part of FIG. 9 is an operation explanatory view of the mechanical brake actuator according to the third embodiment, in which the clip is positioned at the first position with respect to the strut bridge, and the cable end of the brake cable is engaged with the free end of the operation lever. Enlarged view showing the state of abutting engagement with the part The disassembled perspective view which shows the structure of the mechanical brake actuator concerning Example 4. FIG. FIG. 10 is an operation explanatory view of the mechanical brake actuator according to the fourth embodiment, in which the clip is located at the first position with respect to the strut bridge portion, and the cable end of the brake cable is engaged with the free end portion of the operation lever. Enlarged view showing the state of abutting engagement with the part

  Hereinafter, a mechanical brake operating device according to the present invention and a method of connecting a brake cable when the device is completed will be described with reference to the drawings.

A first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a plan view showing an example of a drum brake equipped with a mechanical brake actuator, FIG. 2 is a sectional view of an essential part thereof, FIG. 3 is an exploded perspective view of the mechanical brake actuator, and FIG. Fig. 5 is an enlarged view showing a state in which the rotation in the cable pulling direction is restricted and the connection hole of the free end portion of the operation lever is exposed from the opening of the strut space to the side opposite to the cable pulling direction. FIG. 6 is an enlarged view showing a state where the rotation of the lever in the anti-cable pulling direction is restricted and the connection hole of the free end portion of the operation lever overlaps with the opposing piece of the strut.
The structure of Embodiment 1 of the present invention will be described with reference to the drawings.

A pair of brake shoes 12 and 13 are movably mounted on a back plate 11 fixed to the stationary part 10 of the vehicle body by a shoe hold mechanism (not shown), and one of its adjacent ends is described later. The other adjacent end (not shown) is connected by a connecting member.
A pair of shoe return springs stretched between the brake shoes 12 and 13 (only one shoe return spring 19 is shown) makes contact between one end of the brake shoes 12 and 13 and the anchor 16 and both brake shoes. The contact state of the other end of 12 and 13 and a connection member is maintained.

  A mechanical operating mechanism 22 that expands one adjacent end of each of the brake shoes 12 and 13 includes a strut 23, an operating lever 24, a pivot pin 25, and a locking washer 26. The brake shoes 12 and 13 are inserted adjacent to each other.

The strut 23 is composed of a single plate, and is provided with a bridging portion 23a between both ends in the longitudinal direction, and is bent into a U-shape to form opposing pieces 23b and 23b.
Further, one side of the opposing pieces 23b, 23b facing each other is superposed and tightly joined by welding or the like, and a wide space (gap) 23c is formed between both ends in the longitudinal direction. A narrower space (gap) 23d is connected to the other side.
A shoe engagement groove 23e is formed in one overlapping portion of the facing pieces 23b and 23b, and pivotal support holes 23f and 23f are formed in the other.
The bridging portion 23a connected across the opposing pieces 23b and 23b blocks a part of the wide space 23c.
The bridging portion 23a is a portion where a clip 30 to be described later is sandwiched. On the outer surface of the bridging portion 23a, a protruding portion 23i that functions to position the clip 30 is formed by pressing.
In addition, you may provide the protrusion 23i by the method of welding a different member, or the method of screwing the screw member which has a column-shaped head other than press work.

The operation lever 24 is composed of a single plate, and is sandwiched between the facing pieces 23b and 23b so as to be accommodated in the spaces 23c and 23d of the strut 23.
A shoe engagement groove 24b is formed in the base 24a of the operation lever 24, and a pivot support hole 24d through which the pivot pin 25 is inserted is formed in one protrusion 24c that defines the shoe engagement groove 24b. A stopper washer 26 is attached to the tip of the pivot pin 25 inserted through the pivot holes 23f, 24d, and 23f of the strut 23 and the operation lever 24 so that the operation lever 24 can pivot with respect to the strut 23. It is supported.
A brake cable connecting hole 24f is formed in the free end portion 24e of the operation lever 24 so that a cable end 42 fixed to an end portion of an inner cable 41 constituting a brake cable 40 described later can be connected through a connecting pin 43. ing.

2 on one of the protrusions 24c of the operation lever 24 is in contact with a clip 30 to be described later, thereby restricting the rotation of the operation lever 24 in the cable pulling direction, and the brake cable of the operation lever 24. A stopper 24g is integrally formed to hold the state in which all of the connecting holes 24f are exposed from the wide space 23c of the strut 23.
The position where the stopper 24g is formed may be a position that satisfies the above-described condition (complete exposure of the brake cable connecting hole 24f) by interfering with the clip 30 when the operation lever 24 rotates in the cable pulling direction.

The strut 23 and the operating lever 24 are at least operated until the brake cable connection hole 24f formed in the free end 24e of the operating lever 24 is exposed from the wide space 23c of the strut 23. It is related so that it does not contact the tangle 23a.
With this structure, the cable end 42 fixed to the end of the inner cable 41 is connected to the free end 24e of the operation lever 24 by the connecting pin 43 on the side opposite to the cable pulling direction from the opening of the wide space 23c of the strut 23. Can be connected.

  Note that a cable pulling direction side protrusion 23g that defines the shoe engagement groove 23e of the strut 23 and a cable protrusion direction side protrusion 24h that defines the shoe engagement groove 24b of the operation lever 24 are shown in FIG. Are slidably abutted on the heads of the mounting bolts 20 and 21 shown in FIG.

  The clip 30 is a member that restricts the operation lever 24 from rotating in both the cable pulling direction and the anti-cable pulling direction, and is movably clamped on the bridging portion 23a of the strut 23.

As shown in FIG. 3, the clip 30 of the first embodiment is formed by bending a single strip-shaped spring steel slightly narrower than the transverse width of the bridging portion 23 a of the strut 23 into a U shape or a U shape. The strut 23 is formed so as to elastically hold the bridging portion 23a.
Of the pair of outer sandwiching pieces 31 and inner sandwiching pieces 32 facing each other on both sides of the bent portion 33, the outer sandwiching piece 31 that contacts the outer surface of the bridging portion 23a has a protrusion 23i of the strut 23 described above. A first positioning hole 31a and a second positioning hole 31b that are loosely fitted to each other are formed.
The first and second positioning holes 31a and 31b of the clip 30 are individually fitted into protrusions 23i formed on the outer surface of the bridging portion 23a of the strut 23, thereby being different from the bridging portion 23a ( The clip 30 can be positioned at the first position and the second position.

  A positioning portion 32c is formed on the inner clamping piece 32 that is in contact with the inner surface of the bridging portion 23a. The positioning portion 32c protrudes in a direction away from the outer clamping piece 31 by bending near the end.

  Although the terms “first position” and “second position” are used in the description of the clip 30, in the first embodiment, the first positioning hole 31 a of the clip 30 is formed on the outer surface of the bridging portion 23 a of the strut 23. The state of being fitted and positioned in 23i is defined as the “first position” (FIG. 4), the clip 30 is pushed in, and the second positioning hole 31b of the clip 30 is fitted into the protrusion 23i of the bridging portion 23a of the strut 23. The combined and positioned state is defined as “second position” (FIG. 5).

When the clip 30 sandwiched between the bridging portions 23 a is in the first position, the operation lever 24 rotates in the cable pulling direction so that the stopper 24 g of the operation lever 24 directly contacts the bent portion 33 at the rear end of the clip 30. Limited by contact. Further, the rotation of the operation lever 24 in the anti-cable pulling direction is limited by the middle of the operation lever 24 coming into contact with the positioning portion 32 c of the clip 30. That is, when the clip 30 is in the first position, the brake cable connection hole 24f of the operation lever 24 is held at a position where the entire portion is exposed from the opening of the wide space 23c of the strut 23 to the side opposite to the cable pulling direction (see FIG. 4).
The rotation of the operation lever 24 in the anti-cable pulling direction when the clip 30 is in the first position is restricted by the free end portion 24e side of the operation lever 24 coming into contact with the bridging portion 23a of the strut 23. It may be.
Further, when the clip 30 in which the clip 30 is pushed in the direction separating the bent portion 33 at the rear end of the clip 30 from the stopper 24g of the operation lever 24 and is clamped to the bridging portion 23a is in the second position, the operation lever A position near the free end portion 24e in the middle of 24 abuts on the positioning portion 32c of the clip 30, and the rotation of the operation lever 24 in the anti-cable pulling direction is restricted (FIG. 5).
That is, in the first embodiment, the brake cable connecting hole 24f of the operation lever 24 is moved to the wide width of the strut 23 by moving the clip 30 clamped to the bridging portion 23a of the strut 23 from the first position to the second position. A position where the cable end 42 and the operation lever 24 can be connected by being exposed from the opening of the space 23c in the direction opposite to the cable pulling direction, and the brake cable connection hole 24f of the operation lever 24 overlap with the opposing pieces 23b and 23b of the strut 23. Thus, the brake cable connecting hole 24f can be switched to a position where the brake cable connecting hole 24f is not completely exposed from the opening of the wide space 23c to the side opposite to the cable pulling direction.

  In particular, when the first positioning hole 31a of the clip 30 is fitted to the protrusion 23i formed on the outer surface of the bridging portion 23a to restrict the rotation of the operation lever 24 in the cable pulling direction, The bent portion 33 of the clip 30 and the operation lever 24 are related so that all of the brake cable connecting hole 24f is exposed from the wide space 23c of the strut 23, and the second positioning hole 31b of the clip 30 is connected to the strut. 23, when the rotation of the operation lever 24 in the anti-cable pulling direction is restricted by fitting with the protrusion 23i of the bridging portion 23a of 23, at least a part of the brake cable connection hole 24f has a wide space 23c of the strut 23. The positioning portion 32c of the clip 30 and the operation lever 24 are related to each other so that the connecting pin 43 does not come out. , Reference 5).

  In the first embodiment, the end portion of the outer clamping piece 31 is folded outward so that the opening portion of the clip 30 can be smoothly inserted into the side end of the bridging portion 23a of the strut 23. Is not essential, and may be formed on both the outer sandwich piece 31 and the inner 32 sandwich piece.

The brake cable 40 shown in FIG. 2 includes an outer casing 44 and the like in addition to the inner cable 41 and the cable end 42 described above.
The cable end 42 according to the first embodiment has a clevis shape, and a pair of ear pieces 42 b and 42 b are erected from a base portion 42 a fixed to the inner cable 41, and the cable is connected to the ear pieces 42 b and 42 b via a connecting pin 43. Cable connection holes 42 c and 42 c are formed to connect the end 42 to the operation lever 24.
The end portion of the outer casing 44 includes a casing cap 44a that is fitted to the guide pipe 45 fixed to the anchor 16, and a groove in which the casing cap 44a retaining ring 46 can be fitted is provided.

Next, a method for connecting the brake cable will be described.
FIG. 4 is an enlarged view of the state of the mechanical brake actuator when the clip 30 is in the first position before the brake cable 40 is connected to the operation lever 24, and FIG. The state of the mechanical brake actuator when connected to the lever 24 and when the clip 30 is in the second position is shown.
In FIG. 4, the clip 30 has a pair of inner clamping pieces 32 and outer clamping pieces 31 sandwiched between the inner and outer surfaces of the bridging portion 23a of the strut 23, and the first positioning hole 31a of the bridging portion 23a. The projection 23i formed on the outer surface is fitted and positioned at the first position.
The rotation of the operation lever 24 in the cable pulling direction is limited by the position where the stopper 24g contacts the bent portion 33 of the clip 30 and the rotation of the operation lever 24 in the anti-cable pulling direction is the middle of the operation lever 24. Is limited at a position where it contacts the positioning portion 32c of the clip 30 (see FIG. 4).

Therefore, when the clip 30 sandwiched between the bridging portions 23 a is positioned at the first position, the brake cable connection hole 24 f of the free end portion 24 e of the operation lever 24 is within the strut range of the operation lever 24. The state where all the portions are exposed from the opening of the wide space 23c to the side opposite to the cable pulling direction is maintained.
When an external force is applied to rotate the operation lever 24 in the cable pulling direction, the force is transmitted to the clip 30 through the stopper 24g, and the first positioning hole 31a of the clip 30 is fitted to the protrusion 23i. Since it is firmly supported by the bridging portion 23 a through the joint portion, the state where all the brake cable connection holes 24 f of the operation lever 24 are exposed from the wide space 23 c of the strut 23 is maintained.
The positioning of the clip 30 is limited not only at the position where the first positioning hole 31a and the projection 23i are fitted, but also the side edges of the inner clamping piece 32 lightly abut the hems on both sides of the bridging portion 23a. Therefore, stable positioning is achieved.

  When the inner cable 41 is pinched with a finger and inserted into the guide pipe 45, the cable end 42 passes through the wide space 23c of the strut 23 and reaches the free end 24e of the operation lever 24. The free end portion 24e is accommodated between the ear pieces 42b and 42b of the cable end 42, and the connecting pin 43 is inserted to connect the cable end 42 and the operating lever 24 with the connecting holes 42c, 24f and 42c aligned.

When the cable end 42 is connected to the operation lever 24, the fitting between the first positioning hole 31a of the clip 30 and the protrusion 23i of the bridging portion 23a is released, and the clip 30 is moved to the left in FIG.
When the clip 30 is further moved, the second positioning hole 31b formed in the clip 30 is fitted into the protrusion 23i, and the clip 30 is positioned at the second position advanced with respect to the bridging portion 23a (see FIG. 2, see FIG.
Finally, the casing cap 44a of the outer casing 44 is secured to the other end of the guide pipe 45 with a retaining ring 46 (see FIG. 2).

As the clip 30 is moved and the clamping position is changed to a position close to the free end portion 24e of the operation lever 24, the positioning portion 32c also approaches the free end portion 24e of the operation lever 24.
Accordingly, when the clip 30 is positioned at the second position, when the operation lever 24 tries to rotate in the anti-cable pulling direction thereafter, the operation lever 24 is moved to the clip 30 as shown by a two-dot chain line in FIG. Further contact with the positioning part 32c is restricted.
At this time, the maximum rotation position of the operation lever 24 in the anti-cable pulling direction is that the operation lever 24 is slightly rotated in the anti-cable pulling direction from the state shown in FIG. It is shallower (when the angle is smaller) than when it is in contact with the portion 32c.
Therefore, the connecting pin 43 is always located in the wide space 23 c of the strut 23, and the connecting pin 43 is not physically detached from the cable end 42 and the operation lever 24.

  When it is necessary to release the connection between the cable end 42 and the operation lever 24 due to replacement of the brake cable 40, etc., the clip 30 is operated to the state shown in FIG. 4 while being held by the bridging portion 23a of the strut 23. By retracting the lever 24 to the pivotal support side and rotating the operation lever 24 in the anti-cable pulling direction via the stopper 24g, the connecting pin 43 can be easily pulled out.

In the first embodiment, only the positioning of the clip 30 clamped to the bridging portion 23a at the first position limits the rotation of the operation lever 24 in the cable pulling direction, and the operation lever 24 is moved. It can be held in a predetermined connection position.
Therefore, during transport of the drum brake or connection work of the brake cable 41, the operation lever 24 is prevented from rotating accidentally, and all the brake cable connection holes 24f of the operation lever 24 have the wide strut 23. The state exposed from the space 23c can be maintained.
Furthermore, not only the operation of matching the cable end 42 and the connection holes 42c, 24f, 42c of the operation lever 24 but also the operation of inserting the connection pin 43 into the connection holes 42c, 24f, 42c can be performed in a short time with a simple operation. Therefore, workability is better than conventional.

Next, the mechanical brake actuator according to the second embodiment will be described with reference to FIGS.
In the second embodiment, the clip 50 is used as a completely plane-symmetric shape with no distinction between the front and the back. Since the pair of sandwiching pieces have the same shape, the same reference numerals are originally attached. However, for convenience of explanation, the sandwiching piece that abuts on the outer surface of the bridging portion 23a is defined as the sandwiching piece 51, and the inner surface of the bridging portion 23a is provided. The other sandwiching piece that comes into contact is referred to as a sandwiching piece 52.
The difference from the first embodiment described above is that a) the protrusion 23i of the bridging portion 23a and the first positioning hole 51a and the second positioning hole 51b of the clip 50 matching it are rectangular, and b) A point provided with a guide portion at the tip of the pair of sandwiching pieces 51 and 52, c) a point where the positioning portion of the clip 50 is not formed in a special shape like the positioning portion 32c of the first embodiment, and d) a clip The second positioning hole 52b formed by making 50 a plane-symmetrical shape is used as a stopper engaging hole with which the stopper 24g abuts.

The clip 50 that is slidably clamped to the bridging portion 23a of the strut 23 has a pair of clamping pieces 51 and 52 that are opposed to each other, and the clamping piece 51 has the rectangular protrusion 23i of the strut 23 described above. A rectangular first positioning hole 51a and a second positioning hole 51b that are loosely fitted to each other are formed, and the sandwiching piece 52 has a first shape of the same shape at a position corresponding to the first positioning hole 51a and the second positioning hole 51b. A first positioning hole 52a and a second positioning hole (stopper engagement hole) 52b are formed.
When the clip 50 is in the first position positioned by fitting the first positioning hole 51a of the clip 50 to the protrusion 23i, the stopper 24g formed on one peripheral end surface of the operating lever 24 is the second pinched portion of the clip 50. The second positioning hole (stopper engagement hole) 52b formed in the piece 52 is in contact with the inner end surface on the left side in FIG. 7 to restrict the rotation of the operation lever 24 in the cable pulling direction, and the brake cable connection of the operation lever 24 is performed. The clip 50 and the operation lever 24 are related so that all of the holes 24f are exposed from the wide space 23c of the strut 23 (see FIG. 7).
The first positioning hole 52a formed in the second sandwiching piece 52 of the clip 50 is provided to make the clip 50 completely plane-symmetric, and has no special function.

  The clip 50 is attached by being pushed so as to be sandwiched from the pivot side of the operation lever 24 of the bridging portion 23a of the strut 23, and attached to the bridging portion 23a of the strut 23 by using the elastic force of the clip 50. The position where the first positioning hole 51a of the clip 50 is fitted to the protrusion 23i of the bridging portion 23a is once passed, and the clip 50 is returned in the reverse direction while rotating the operation lever 24 in the anti-cable pulling direction. When the one positioning hole 51a is fitted into the protrusion 23i, the clip 50 can be easily attached.

When the clip 50 is positioned at the first position by fitting the first positioning hole 51a of the clip 50 to the protrusion 23i of the bridge portion 23a, the rotation of the operation lever 24 in the cable pulling direction is caused by the bridge. The stopper 24g comes into contact with the second positioning hole (stopper engagement hole) 52b of the clip 50 clamped to the portion 23a, and the operation lever 24 is rotated in the anti-cable pulling direction. A portion near the free end portion 24e in the middle of the strut 23 is in contact with the inner end portion of the bridging portion 23a of the strut 23 and is restricted.
When the clip 50 is positioned at the first position with respect to the bridging portion 23a, the entire brake cable connection hole 24f of the operation lever 24 is set in advance so as to be exposed from the opening portion of the wide space 23c of the strut 23. Therefore, it is easy to connect the operation lever 24 and the cable end 42 by inserting the connecting pin 43.

When the connection between the operation lever 24 and the cable end 42 is completed, the clip 50 is pushed in, the second positioning hole 51b of the clip 50 is fitted into the protrusion 23i, and the clamping position of the clip 50 is changed to the second position.
As the clip 50 is slid along the bridging portion 23a to move the clip 50 from the first position to the second position, the inner end surface on the right side of the second positioning hole 52b of the clip 50 in FIG. The lower surface of the sandwiching piece 52 pushes the stopper 24g of the operation lever 24. As a result, the stopper 24g of the operation lever 24 is positioned below the lower surface of the sandwiching piece 52 in FIG. At this time, the maximum rotation position of the operation lever 24 in the anti-cable pulling direction is limited by the position where the stopper 24g contacts the lower surface of the sandwiching piece 52 (see FIG. 8).
Therefore, after that, the connecting pin 43 is always located in the wide space 23c of the strut 23, and the cable end 42 is not physically detached from the operation lever 24.

  In the second embodiment, in addition to the same advantages as those of the first embodiment described above, the stopper 24g of the operation lever 24 can be formed close to the free end portion 24e. Therefore, there is an advantage that the stopper 24g does not get in the way when the clip 50 is attached to the bridging portion 23a of the strut 23.

  In addition, there is no need to provide a specially-shaped positioning portion on the clip 50, and further, the entire length can be shortened, so that the manufacturing cost of the clip 50 can be reduced.

  Further, since the fitting shape of the clip 50 and the protrusion 23i is rectangular, the lateral blurring of the clip 50 is limited only at the fitting portion. Therefore, the length of the bridging portion 23a of the strut 23 (the wide space 23c is reduced). Even if the distance between the opposing pieces 23b and 23b to be formed is increased, the lateral blur is limited by lightly abutting both side edges of the sandwiching piece 52 to the skirts on both sides of the bridging portion 23a as in the first embodiment. Since there is no need, the size of the clip 50 can be reduced.

  Further, since the clip 50 can be formed in a plane-symmetric shape, there is an advantage that the front and back sides are eliminated and the handling is simplified.

Next, based on FIGS. 9 and 10, a cable end engaging portion 24 k is formed on the lower surface of the free end portion 24 e of the operation lever 24 to be engaged with the base portion 42 a of the clevis-type cable end 42. When the base portion 42a of the operation lever 24 is engaged with the cable end engagement portion 24k of the operation lever 24, the connection holes 42c, 24f, 42c of the cable end 42 and the operation lever 24 are vertically arranged at positions where the connection pins 43 can be inserted. A mechanical brake actuator according to Example 3 will be described.
In the third embodiment, although the case where the clip 30 of the first embodiment described above is used is shown, the clip 50 described in the second embodiment may be used.

In the operation lever 24 according to the third embodiment, a shelf-like cable end engaging portion 24k is formed on the lower surface of the free end portion 24e immediately below the brake cable connecting hole 24f, and the right end and the protruding portion of the cable end engaging portion 24k are formed. An inclined guide surface 24m is formed between 24h.
When the base portion 42a of the cable end 42 comes into contact with and engages with the cable end engaging portion 24k, the connection holes 42c, 24f, and 42c of the cable end 42 and the operating lever 24 are almost at positions where the connection pins 43 can be inserted. They are related in a column.

Next, a method for connecting the cable end 42 and the operation lever 24 will be described.
When the clip 30 is in the first position, the operation lever 24 is restricted from rotating in the cable pulling direction and the anti-cable pulling direction, and the entire brake cable connection hole 24f formed in the free end 24e of the operation lever 24 is The state where all the openings of the strut 23 are exposed is maintained.
A pair of ear pieces 42b and 42b formed in the cable end 42 introduced into the wide space 23c of the strut 23 by pushing the inner cable 41 are fitted into the free end 24e of the operation lever 24, and the base 42a is brought into contact with the guide surface 24m. Make contact.
When the inner cable 41 is further pushed in, the operating lever 24 is slightly rotated around the pivot pin 25 and comes into contact with the positioning portion 32c of the clip 30, and thereafter, one edge of the base portion 42a moves on the guide surface 24m. Then, the cable end engaging portion 24k approaches.
When the base portion 42a reaches the end of the guide surface 24m, the base portion 42a comes into contact with and engages with the stepped cable end engaging portion 24k, and further movement is restricted (see FIG. 10).
The connecting pin 43 is inserted through the connecting holes 42c, 24f, 42c that are substantially in a column.
Similar to the first embodiment, the clip 30 is moved to complete the connection between the cable end 42 and the operation lever 24.

  In the third embodiment, in addition to the same advantages as those of the first or second embodiment described above, the pair of ear pieces 42b and 42b of the cable end 42 are fitted to the free end portion 24e of the operation lever 24. By simply pushing the inner cable 41 in the state, the cable end 42 and the connecting holes 42c, 24f, 42c of the operation lever 24 can be vertically arranged at a position where the connecting pin 43 can be inserted. There is an advantage that the connection work between the control lever 42 and the operation lever 24 can be performed more accurately in a short time.

  Although the case where the cable end 42 has a bifurcated shape (clevis type) has been described in the first to third embodiments, the present invention can also be applied to the case where the operation lever 24 has a bifurcated shape. A cable end engagement in which a pair of flange portions 42d and 42d formed on a plate-like cable end 42 come into contact with and engage with the lower surface of the bifurcated free end portion 24e of the operating lever 24 based on FIGS. Portion 24k is formed, and when the flange portions 42d and 42d of the cable end 42 are engaged with the cable end engaging portion 24k of the operation lever 24, the connection holes 24f, 42c and 24f of the operation lever 24 and the cable end 42 are connected. A mechanical brake actuating device according to a fourth embodiment in which the pins 43 are vertically inserted at positions where the pins 43 can be inserted will be described.

The operation lever 24 according to the fourth embodiment has a brake cable connection hole 24f formed in a free end portion 24e formed in a bifurcated shape, and a bifurcated free end portion directly below the brake cable connection hole 24f. A shelf-like cable end engaging portion 24k is formed on the lower surface of 24e, and an inclined guide surface 24m is formed on the lower surface of a pair of opposed pieces 24n continuous from the right end of the cable end engaging portion 24k.
In the cable end 42 according to the fourth embodiment, a base portion 42a is integrally formed with a pair of flange portions 42d and 42d and a plate-like portion 42e having a connection hole 42c.
When the flange portion 42d of the cable end 42 comes into contact with and engages with the cable end engaging portion 24k, the connection holes 24f, 42c, and 24f of the operation lever 24 and the cable end 42 are in positions where the connection pins 43 can be inserted. They are related so that they are almost in tandem.

Next, a method for connecting the cable end 42 and the operation lever 24 will be described.
When the clip 30 is in the first position, the operation lever 24 is restricted from rotating in the cable pulling direction and the anti-cable pulling direction, and the brake cable connecting hole formed in the bifurcated free end portion 24e of the operation lever 24 is provided. The state where the entire 24f is exposed from the opening of the strut 23 is maintained.
The plate-like portion 42e introduced into the wide space 23c of the strut 23 by pushing the inner cable 41 is fitted into the bifurcated free end portion 24e, and the flange portion 42d is brought into contact with the guide surface 24m.
When the inner cable 41 is further pushed in, one edge of the flange portion 42d moves on the guide surface 24m and approaches the cable end engaging portion 24k.
When the flange portion 42d reaches the terminal end of the guide surface 24m, the flange portion 42d comes into contact with and engages with the stepped cable end engaging portion 24k, and further movement is restricted.
The connection pin 43 is inserted through the connection holes 24f, 42c, and 24f that are substantially in line.
Similar to the first embodiment, the clip 30 is moved to complete the connection between the cable end 42 and the operation lever 24.
In the fourth embodiment, the case where the clip 30 of the first embodiment described above is used will be described. However, the clip 50 described in the second embodiment may be used.

  In the fourth embodiment, when the combination of the shapes of the operation lever and the cable end is different, the same advantages as those of the third embodiment described above can be obtained.

DESCRIPTION OF SYMBOLS 10 Car body stationary part 11 Back plate 12, 13 Brake shoe 16 Anchor 16a Standing part 19 Shoe return springs 20, 21 Mounting bolt 22 Mechanical operating mechanism 23 Strut 23a Bridge part 23b Opposing piece 23c Wide space 23d Narrow space Space 23e Shoe engaging groove 23f Pivoting hole 23g Protruding part 23i Protruding part 24 Operating lever 24a Base part 24b Shoe engaging groove 24c One projecting part 24d Pivoting hole 24e Free end part 24f Brake cable connecting hole 24g Stopper 24h The other projection Portion 24k Cable end engagement portion 24m Guide surface 24n Opposing piece 25 Pivoting pin 26 Stop washer 30, 50 Clip 31 Outer clamping piece 31a First positioning hole 31b Second positioning hole 32 Inner clamping piece 32c Positioning portion 33 Bending portion 40 Brake cable 41 Inner Table 42 Cable end 42a Base 42b Ear piece 42c Connection hole 42d Flange 42e Plate-like part 43 Connection pin 44 Outer casing 44a Casing cap 45 Guide pipe 46 Stop ring 51 First clamping piece 51a First positioning hole 51b Second positioning hole 52 2nd clamping piece 52a 1st positioning hole 52b 2nd positioning hole (stopper engagement hole)

Claims (5)

A strut having a pair of opposing pieces engaged with one brake shoe and connected by a bridging portion, and engaged with the other brake shoe and accommodated in a space between the opposing pieces of the struts, and can be rotated. And an operation lever pivotally supported by
When the brake cable connected to the free end of the operation lever with a connecting pin is pulled, the operation lever and the strut are relatively rotated so that both expand in opposite directions,
Comprising a clip slidably attached to the strut bridge;
When the clip is positioned at the first position with respect to the strut bridging portion, the operation lever so that the brake cable connection hole formed in the free end portion of the operation lever is completely exposed from the space of the strut. Until the contact with the bridge or the clip, the operation lever is allowed to rotate in the anti-cable pulling direction, and the clip is positioned at the second position with respect to the strut bridge. In the mechanical brake actuator, the operation lever is in contact with the clip and the rotation of the operation lever in the anti-cable pulling direction is restricted so that the brake cable connection hole is not completely exposed from the space of the strut. ,
When the clip is positioned at the first position, the operation lever abuts on the clip so that the brake cable connection hole formed in the free end of the operation lever is exposed from the space of the strut. Limiting the rotation of the operation lever in the cable pulling direction,
Mechanical brake actuator.   A stopper capable of coming into contact with the clip is formed on the peripheral end surface of the operation lever, and when the clip is in the first position, the stopper comes into contact with the clip and holds the operation lever in a position where the connection work is possible. The mechanical brake actuator according to claim 1, wherein:   An engagement portion is formed on the peripheral end surface of the free end portion of the operation lever so as to abut and engage with a cable end fixed to the end portion of the brake cable, and the cable end is engaged with the engagement portion of the operation lever. The mechanical brake actuating device according to claim 1 or 2, characterized in that when the positioning is performed, both connection holes of the cable end and the operation lever are arranged in a line on substantially the same axis.   The clip has a pair of sandwiching pieces that sandwich the strut bridging portion, and positioning that restricts rotation of the operation lever in the anti-cable pulling direction by contacting the operation lever to a part of the sandwiching piece. The mechanical brake actuator according to any one of claims 1 to 3, further comprising a portion.   The clip includes a first positioning hole and a second positioning hole that are loosely fitted to a protrusion formed on an outer surface of a strut bridging portion, and the first and second positioning holes of the clip are formed in the protrusion of the strut. The mechanical brake actuator according to claim 4, wherein the clips are individually fitted and positioned at different positions with respect to the bridge portion.

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