JP6896520B2 - Vehicle drum brake device - Google Patents

Description

The present invention relates to a vehicle drum brake device in which an actuator case of an electric actuator that obtains a parking brake state during operation is attached to a back plate.

An electric actuator that operates to obtain parking braking force is attached to the back plate of the drum brake, and the actuator case of the electric actuator is provided with a connector portion that projects laterally from the actuator case. , Known in Patent Document 1.

Japanese Patent Publication No. 2014-504711

However, in the case disclosed in Patent Document 1, since the connector portion is arranged at a fixed position with respect to the actuator case, it is not versatile and the actuator case must be manufactured according to the layout of each vehicle model. , Invites an increase in cost.

The present invention has been made in view of such circumstances, and the position of the connector portion with respect to the actuator case can be easily changed to provide versatility, and by making it compatible with a wide variety of vehicles, an increase in cost can be suppressed. It is an object of the present invention to provide a drum brake device for a vehicle which has been made available.

In order to achieve the above object, in the present invention, in a vehicle drum brake device in which an actuator case of an electric actuator that obtains a parking brake state at the time of operation is attached to a back plate, the actuator case sets the parking brake state. A case main body having a housing cylinder portion for accommodating an electric drive source that exerts power for obtaining the electric drive source so that a part of the electric drive source faces the outside, and the accommodation that covers the part of the electric drive source. It integrally has a lid portion to be coupled to the cylinder portion and a connector portion that projects laterally from the lid portion and is arranged on the side of the accommodating cylinder portion so that a terminal connected to the electric drive source is arranged. First, the cover member is provided with a cover member, and the cover member can be arbitrarily selected at at least a plurality of locations relative to the accommodating cylinder portion in the circumferential direction, and is coupled to the accommodating cylinder portion. It is a feature of.

In the present invention, in addition to the configuration of the first feature, a plurality of locking recesses are formed on one of the protruding end portion of the electric drive source from the accommodating cylinder portion and the lid portion of the cover member. The second feature is that a plurality of engaging protrusions that engage with the locking recess are projected from the other of the protruding end portion of the electric drive source from the accommodating cylinder portion and the lid portion of the cover member. And.

In the present invention, in addition to the configuration of the second feature, the engaging protrusion is divided into two in the circumferential direction of the lid so as to be elastically engaged with the locking recess. The third feature is that it is formed in a character shape.

In the present invention, in addition to any of the configurations of the first to third features, the joint portion between the accommodating cylinder portion and the lid portion is formed so as to have a circular or regular polygonal cross-sectional shape. This is the fourth feature.

In the present invention, in addition to any of the configurations of the first to fourth features, the actuator case in which the terminal arranged in the connector portion is directed to the rear side in the front-rear direction of the vehicle is the back plate of the rear wheel. The fifth feature is that the vehicle is mounted on the rear side in the front-rear direction of the vehicle.

The sixth feature of the present invention is that, in addition to any of the configurations of the first to fifth features, the cover member is bonded or welded to the storage cylinder portion.

Further, the present invention has a seventh feature that the electric drive source is an electric motor, in addition to any of the configurations of the first to sixth features.

The first accommodating cylinder portion 45 of the embodiment corresponds to the accommodating cylinder portion of the present invention, and the first cover member 48 of the embodiment corresponds to the cover member of the present invention.

According to the above-mentioned features of the present invention, the connector portion integrally possessed by the cover member is arranged on the side of the accommodating cylinder portion of the actuator case, and the lid portion forming a part of the cover member is the connector portion with respect to the accommodating cylinder portion. Since it is possible to arbitrarily select the relative position in the circumferential direction at least at multiple locations and it is coupled to the accommodating cylinder, the position of the connector with respect to the actuator case while eliminating the need to make an actuator case according to the layout of each vehicle model. It is possible to suppress the increase in cost by making it easy to change and giving it versatility and making it compatible with many types of vehicles.

Further, in particular, according to the second feature, the electric drive is carried out by engaging the other engaging protrusion with one of the locking recesses of the protruding end of the electric drive source from the accommodating cylinder and the lid of the cover member. The position of the lid portion and thus the connector portion in the circumferential direction relative to the source can be fixed.

In particular, according to the third feature, the electric drive source and the lid can be more reliably engaged by elastically engaging the lid and the electric drive source of the cover member.

In particular, according to the fourth feature, since the joint portion between the accommodating cylinder portion and the lid portion has a circular or regular polygonal cross-sectional shape, the degree of freedom in the position of the connector portion with respect to the actuator case is increased, and the degree of freedom of the position of the connector portion is increased. The orientation can be easily changed.

In particular, according to the fifth feature, the actuator case is attached to the rear side of the back plate of the rear wheel in the vehicle front-rear direction , and the terminals arranged in the connector portion face the rear side in the vehicle front-rear direction. It is possible to improve the maintainability of the part and protect the terminals of the connector part from flying stones generated when the vehicle is running.

Further, in particular, according to the sixth feature, since the cover member is bonded or welded to the accommodating cylinder portion, the orientation of the connector portion can be easily oriented without increasing the number of parts when the cover member is bonded to the accommodating cylinder portion. The cover member can be securely connected to the accommodating cylinder portion while being able to be changed to.

It is a front view of the drum brake device. It is a cross-sectional view taken along the line 2-2 of FIG. It is a perspective view seen from the 3 arrow view direction of FIG. FIG. 3 is a cross-sectional view taken along line 4-4 of FIG. 3 in a state where the brake cable is loosened. It is sectional drawing corresponding to FIG. 4 in the state which pulled the brake cable. 6-6 is a cross-sectional view taken along the line 6-6 of FIG. It is a perspective view of an electric actuator. It is an exploded perspective view of an electric motor and an actuator case. 9-9 is a cross-sectional view taken along the line 9-9 of FIG.

An embodiment of the present invention will be described with reference to FIGS. 1 to 9 attached. First, in FIGS. 1 to 3, a drum brake device 11 according to the present invention is provided on, for example, the left rear wheel of a four-wheeled vehicle. The drum brake device 11 is slid on the inner circumference of a fixed back plate 13 having a through hole 12 in the center for penetrating the axle 10 of the left rear wheel and a brake drum 14 rotating together with the left rear wheel. The first and second brake shoes 15 and 16 arranged in the back plate 13 so as to be in contact with each other and the first and second brake shoes 15 and 16 exert a force for extended operation. Braking gap automatic adjusting means (so-called auto adjuster) 18 that automatically adjusts the gap between the wheel cylinder 17 fixed to the upper part of the back plate 13 and the first and second brake shoes 15 and 16 and the brake drum 14. And a return spring 19 provided between the first and second brake shoes 15 and 16.

The first and second brake shoes 15 and 16 are connected to the webs 15a and 16a formed in a bow shape along the inner circumference of the brake drum 14 and so as to be orthogonal to the outer periphery of the webs 15a and 16a. The rims 15b and 16b are formed, and the linings 15c and 16c attached to the outer periphery of the rims 15b and 16b.

The outer end portions of the pair of pistons 20 included in the wheel cylinder 17 are arranged so as to face the webs 15a and 16a at the upper end portions of the first and second brake shoes 15 and 16. Further, at the lower part of the back plate 13, an anchor block 21 serving as a fulcrum at the time of expansion and contraction of the first and second brake shoes 15 and 16 is provided at one end of the first and second brake shoes 15 and 16 ( In this embodiment, the wheel cylinder 17 is fixed so as to support the lower end portion), and the wheel cylinder 17 is operated by the output hydraulic pressure of a master cylinder (not shown) operated by a brake pedal, and the anchor With the block 21 as the fulcrum, the force for driving the first and second brake shoes 15 and 16 to the expanding side is exerted.

A coil spring 22 for urging the lower ends of the webs 15a and 16a of the first and second brake shoes 15 and 16 toward the anchor block 21 is provided between the lower ends of the webs 15a and 16a. The return spring 19 for urging the first and second brake shoes 15 and 16 in the contraction direction is provided between the upper ends of the webs 15a and 16a of the first and second brake shoes 15 and 16.

The braking gap automatic adjusting means 18 is provided between the webs 15a and 16a of the first and second brake shoes 15 and 16, and has a contraction position regulating strut 24 that can be extended by rotation of the adjusting gear 23, and the adjusting gear. An adjust that has a feed claw 25a that engages with 23 and is rotatably supported by the web 16a of the second brake shoe 16 that is one of the first and second brake shoes 15 and 16. It is composed of a lever 25 and an adjust spring 26 that rotationally urges the adjust lever 25 to rotate the adjust gear 23 in a direction in which the contraction position restricting strut 24 is extended.

The contraction position regulating strut 24 regulates the contraction positions of the first and second brake shoes 15 and 16, and the first brake shoe 15 of the first and second brake shoes 15 and 16 is provided. A first rod 27 having a first engaging portion 27a that engages with the upper part of the web 15a, and a second engaging portion 28a having a second engaging portion 28a that engages with the upper part of the web 16a included in the second brake shoe 16. The second rod 28, which is arranged coaxially with the first rod 27, and the adjust bolt, one end of which is inserted into the first rod 27 so as to be movable in the axial direction and the other end of which is screwed coaxially to the second rod 28. The adjusting gear 23 is arranged between the first and second rods 27 and 28 and is formed on the outer periphery of the adjusting bolt 29.

A first locking recess 30 for engaging the first engaging portion 27a is provided on the upper portion of the web 15a of the first brake shoe 15, and a first locking recess 30 is provided on the upper portion of the web 16a of the second brake shoe 16. A second locking recess 31 for engaging the two engaging portions 28a is provided.

The adjusting lever 25 having a feed claw 25a that engages with the adjusting gear 23 is rotatably supported by the web 16a of the second brake shoe 16 via a support shaft 32, and is supported by the second brake shoe 16 as described above. The adjusting spring 26 is provided between the web 16a and the adjusting lever 25. Moreover, the spring force of the adjust spring 26 is set to be smaller than the spring force of the return spring 19.

According to such a braking gap automatic adjusting means 18, when the first and second brake shoes 15 and 16 are extended by the operation of the wheel cylinder 17, a constant value is caused due to wear of the linings 15c and 16c. When expanded as described above, the adjusting lever 25 is rotated around the axis of the support shaft 32 by the spring force of the adjusting spring 26, and the contraction position is regulated in response to the rotation of the adjusting gear 23. The effective length of the strut 24 is increased and corrected.

By the way, in the drum brake device 11, one end of the first and second brake shoes 15 and 16 is rotatably supported by the web 15a of the first brake shoe 15, and the contraction position regulating strut 24 A parking brake lever 34 that is engaged with one end is provided.

The parking brake lever 34 extends vertically so as to partially overlap the web 15a in the first brake shoe-15 in a front view, and the upper end portion of the parking brake lever 34 is a first brake. A first engaging portion 27a included in the contraction position regulating strut 24 is engaged with the upper part of the web 15a of the shoe 15 via a pin 35, and the upper part of the parking brake lever 34.

When the parking brake of the vehicle is activated, the parking brake lever 34 is rotated and driven in the counterclockwise direction of FIG. 1 with the pin 35 as a fulcrum, and the rotation of the parking brake lever 34 causes a second brake. A force in a direction in which the lining 16c of the brake shoe 16 is pressed against the inner circumference of the brake drum 14 acts on the shoe 16 via the contraction position regulating strut 24. Further, when the parking brake lever 34 is continuously rotated and driven in the counterclockwise direction of FIG. 1, the parking brake lever 34 uses the engagement point of the contraction position regulating strut 24 with the first engaging portion 27a as a fulcrum. rotates, in turn, first brake shoe 1 5 via the pin 35 is extended operational, so that the lining 15c of the first brake shoe 15 is pressed against the inner periphery of the brake drum 14. That is, the parking brake lever 34 operates at an operating position where the linings 15c and 16c of the first and second brake shoes 15 and 16 are in pressure contact with the inner circumference of the brake drum 14, and the parking brake is in this state. The state will be obtained.

When the application of the rotational driving force to the parking brake lever 34 is stopped, the first and second brake shoes 15 and 16 are operated by the spring force of the return spring 19 in the direction away from the inner circumference of the brake drum 14. At the same time, the parking brake lever 34 returns to the non-operating position, and the parking brake lever 34 is urged toward the non-operating position side.

The parking brake lever 34 is rotationally driven by the power exerted by the electric actuator 36, and the brake cable 37 towed by the electric actuator 36 is pulled by the brake cable 37 to pull the second brake shoe 1. The parking brake lever 34 is rotationally driven so as to press the contraction position regulating strut 24 against the web 16 a of No. 6 to obtain a parking brake state, and is connected to the lower portion of the parking brake lever 34. ..

With reference to FIGS. 4 and 5, the electric actuator 36 enables the screw shaft 38 connected to the brake cable 37 and the screw shaft 38 to reciprocate in the axial direction while preventing the rotation of the screw shaft 38. A supporting actuator case 39, an electric motor 40 as an electric drive source supported by the actuator case 39 with free forward and reverse rotation, and a rotational motion generated by the electric motor 40 are converted into a linear motion of the screw shaft 38. It is provided with a motion conversion mechanism 41 interposed between the electric motor 40 and the screw shaft 38 and housed in the actuator case 39.

A bottomed connecting hole 42 is coaxially provided at the end of the screw shaft 38 on the brake cable 37 side, and the end of the brake cable 37 on the electric actuator 36 side is inserted into the connecting hole 42. Will be done. Moreover, an annular groove 43 is formed on the outer periphery of the screw shaft 38 near the opening end of the connecting hole 42, and a part of the screw shaft 38 is formed in a state where the brake cable 37 is inserted into the connecting hole 42. By crimping the annular groove 43 so as to bite into the brake cable 37, the screw shaft 38 is connected to the brake cable 37.

The brake cable 37 is pulled out into the back plate 13 from the electric actuator 36 attached to the back plate 13, and an engaging piece 44 fixed to the other end of the brake cable 37 is a parking brake lever. Engage with the lower end of 34.

As shown in FIG. 5, the electric actuator 36 moves the screw shaft 38 to the side that pulls the brake cable 37 in order to drive the parking brake lever 34 toward the operating position side, as shown in FIG. 4, and as shown in FIG. The state in which the screw shaft 38 is moved to the side where the brake cable 37 is loosened in order to return the parking brake lever 34 from the operating position to the non-operating position side is switched by changing the rotation direction of the electric motor 40.

With reference to FIG. 6, the anchor block 21 is fixed to the lower part of the back plate 13 by a pair of rivets 82 together with a cable guide 81 that sandwiches the anchor block 21 with the lower part of the back plate 13. As shown in FIG. 2, the cable guide 81 is integrally provided with a guide portion 81a for guiding the brake cable 37 so as to have a substantially U-shaped cross-sectional shape, and a stopper 81b. Are provided integrally.

As shown by the chain line in FIGS. 1 and 2, the operating end of the parking brake lever 34 is regulated by bringing the lower end portion of the parking brake lever 34 into contact with the stopper 81b in the parking brake state.

Further, the stopper 81b is configured to have elasticity, and in this embodiment, the cable guide 81 bends and exerts elasticity when the parking brake lever 34 comes into contact with the stopper 81b. It is formed in the shape of a thin plate.

With reference to FIG. 7, the actuator case 39 is coupled to the case main body 47 having the first and second accommodating cylinders 45 and 46 integrally and the open end of the first accommodating cylinder 45. It is composed of a first cover member 48 and a second cover member 49 coupled to the case main body 47 from the side opposite to the first cover member 48.

The first accommodating cylinder portion 45 is formed in a bottomed cylindrical shape so that a first end wall portion 45a is provided at one end portion, and is fitted to a central portion of the first end wall portion 45a. The holes 50 are formed coaxially. The second accommodating cylinder portion 46 is arranged on the side of the first accommodating cylinder portion 45, has one end opened, and is arranged in the intermediate portion in the longitudinal direction of the first accommodating cylinder portion 45. A bottomed cylindrical shape is formed so that the other end is closed by the end wall portion 46a, and a cylindrical support cylinder portion 46b through which the screw shaft 38 is passed is provided at the center portion of the second end wall portion 46a. It is thrust together.

With reference to FIG. 8, a cylindrical first bearing portion 53a that rotatably supports the motor shaft 54 is projected from one end in the axial direction of the motor case 53 of the electric motor 40, and the motor shaft One end of the 54 penetrates the first bearing 53a and protrudes from one end of the motor case 53, and the other end of the motor shaft 54 is rotatable at the other end of the motor case 53 in the axial direction. A bottomed cylindrical second bearing portion 53b to be supported is projected.

In the electric motor 40, one end of the motor case 53 is brought into contact with the first end wall portion 45a while fitting the first bearing portion 53a into the fitting hole 50 of the case main body 47. In this way, it is accommodated in the first accommodating cylinder portion 45, and a part of the electric motor 40, in this embodiment, the other end portion of the motor case 53 on the side where the second bearing portion 53b is provided. The electric motor 40 is accommodated in the first accommodating cylinder portion 45 so as to face the outside.

The first cover member 48 covers a portion of the electric motor 40 housed in the first storage cylinder portion 45 that faces the outside from the first storage cylinder portion 45 of the first storage cylinder portion 45. A lid portion 48a coupled to the opening end and a terminal 55 (see FIG. 3) connected to the electric motor 40 are arranged so as to project laterally from the lid portion 48a and the first accommodating cylinder portion. A wave washer 56 is interposed between the second bearing portion 53b and the lid portion 48a of the electric motor 40, which integrally has a connector portion 48b arranged on the side of the 45.

Moreover, the first cover member 48 can arbitrarily select the position of the connector portion 48b relative to the first accommodating cylinder portion 45 in the circumferential direction at at least a plurality of locations around the axis of the first accommodating cylinder portion 45. It is possible that the first accommodating cylinder portion 45 is coupled to the first accommodating cylinder portion 45, and the connecting portion 57 of the first accommodating cylinder portion 45 and the lid portion 48a has a circular or regular polygonal cross-sectional shape. It is formed and bonded by adhesion or welding.

In this embodiment, the lid portion 48a is formed in a dish shape open to the side of the first storage cylinder portion 45, and the first lid portion 48a has a circular cross-sectional shape at the open end. An annular recess 58 coaxial with the accommodating cylinder portion 45 of the above is formed. On the other hand, a ring-shaped fitting protrusion 59 that fits into the annular recess 58 is provided at the open end of the first storage cylinder 45, and the joint portion 57 is formed in the annular recess 58. The lid portion 48a and the first accommodating cylinder portion 45 are adhered to each other in a state where the fitting protrusion 59 is fitted, and has a circular cross-sectional shape.

Paying attention to FIG. 8, the protruding end portion of the motor case 53 of the motor case 53 from the first accommodating cylinder portion 45, that is, the other end portion of the motor case 53 and the lid of the first cover member 48. A plurality of locking recesses 51 are formed on one of the portions 48a, and a plurality of engaging protrusions 52 that engage with the locking recesses 51 are formed on the other end of the motor case 53 and the other of the lid 48a. Be thrust. According to this embodiment, on the outer periphery of the other end of the motor case 53, locking recesses 51 arranged at a plurality of locations, for example, two locations spaced apart from each other in the circumferential direction are formed, and the lid portion 48a is formed. At a position inward in the radial direction from the annular recess 58, a plurality of, for example, a pair of engaging protrusions 52 that are engaged with the locking recess 51 are projected. Moreover, the engaging protrusion 52 is formed in a U shape divided into two in the circumferential direction of the lid portion 48a so as to be elastically engaged with the locking recess 51.

By engaging the engaging protrusion 52 with the locking recess 51, the relative positions of the electric motor 40 and the first cover member 48 in the circumferential direction are fixedly determined, and the motor case 53 The terminal receiving portion 55a, which is capable of inserting and connecting a terminal (not shown) on the side of the electric motor 40 protruding from the other end portion of the above, is a lid portion inward in the radial direction from the annular recess 58. The lid portion 48a is projected from the 48a so as to project toward the electric motor 40 side, and these terminal receiving portions 55a are formed so as to be connected to the terminal 55 in the connector portion 48b.

The second cover member 49 is coupled to the case main body 47 so as to form a gear chamber 60 with the case main body 47. In this connection, the second cover member 49 may be bonded or welded to the case main body 47. Further, the motion conversion mechanism 41 includes a nut 61 screwed into the screw shaft 38 as one component, and is housed in the gear chamber 60.

The motion conversion mechanism 41 includes a drive gear 62 provided on the motor shaft 54 of the electric motor 40, an intermediate large diameter gear 63 that meshes with the drive gear 62, and an intermediate small diameter gear that rotates together with the intermediate large diameter gear 63. 64, the nut 61, and a driven gear 65 provided on the nut 61 and meshed with the intermediate small diameter gear 64.

The intermediate large-diameter gear 63 and the intermediate small-diameter gear 64 are integrally formed, and are rotatably supported by a support shaft 66 parallel to the motor shaft 54 and the screw shaft 38. Both ends of the support shaft 66 are supported by the case main body 47 and the second cover member 49.

The nut 61 has a radius from a large-diameter cylindrical portion 61a rotatably housed in the second accommodating cylinder portion 46 and an end portion of the large-diameter cylindrical portion 61a opposite to the second cover member 49. A small-diameter cylindrical portion 61c that is connected to the inner peripheral edge of the inwardly-facing flange portion 61b that projects inward in the direction and extends to the side opposite to the second cover member 49 and penetrates the screw shaft 38. And an outward flange portion 61d that projects outward in the radial direction from the end portion of the large-diameter cylindrical portion 61a on the side of the second cover member 49. A female screw 67 screwed to the screw shaft 38 is engraved on the inner circumference of the small-diameter cylindrical portion 61c, and the driven gear 65 is formed on the outer circumference of the outward flange portion 61d. A ball bearing 68 is interposed between the small-diameter cylindrical portion 61c and the end of the second accommodating cylinder portion 46 on the second end wall portion 46a side.

A flange portion 38a that projects outward in the radial direction is provided at the end of the screw shaft 38 on the side opposite to the brake cable 37. On the other hand, the nut 61 is formed so that the recess 70 defined by the large-diameter cylindrical portion 61a and the inward flange portion 61b of the nut 61 opens toward the flange portion 38a.

By the way, when the brake cable 37 is pulled to drive the parking brake lever 34 toward the operating position, the screw shaft 38 moves to the side where the flange portion 38a separates from the nut 61 as shown in FIG. Then, when the brake cable 37 is loosened in order to return the parking brake lever 34 from the operating position to the non-operating position side, the flange portion 38a moves to the side close to the nut 61 as shown in FIG. When the screw shaft 38 moves in the direction of loosening the brake cable 37, the flange portion 38a is interposed between the flange portion 38a and the nut 61 to urge the flange portion 38a to separate from the nut 61. A plurality of countersunk springs 71 as elastic members that exert elastic force are housed in the recess 70.

The recess 70 accommodates a plurality of the disc springs 71 and a disk-shaped retainer 72 that sandwiches the disc springs 71 between the inward flange portion 61b of the nut 61.

With reference to FIG. 9, the flange portion 38a is formed so as to project radially outward from the screw shaft 38 in a direction along one diameter line of the screw shaft 38. On the other hand, the second cover member 49 of the actuator case 39 is integrally formed with a bottomed cylindrical guide cylinder portion 49a surrounding the screw shaft 38, and the inner surface of the guide cylinder portion 49a is formed on the inner surface of the guide cylinder portion 49a. A pair of locking grooves 73 extending in a direction along the axis of the screw shaft 38 and slidably engaging the flange portion 38a are formed.

A bearing member 74 that receives a thrust load from the nut 61 is interposed between the open end of the guide cylinder portion 49a and the nut 61, and the bearing member 74 is short that is inserted into the recess 70. It has a cylindrical portion 74a integrally.

Here, as shown in FIG. 5, when the brake cable 37 is pulled to drive the parking brake lever 34 from the non-operating position to the operating position side, the outer peripheral portion of the retainer 72 is the bearing member. By contacting the short cylindrical portion 74a of the 74, the disc spring 71 is prevented from being detached from the recess 70. Further, as shown in FIG. 4, when the screw shaft 38 moves so as to loosen the brake cable 37, the elastic force of the disc spring 71 acts on the flange portion 38a via the retainer 72.

By the way, the back plate 13 of the drum brake device 11 mounted on the left rear wheel is integrally provided with a mounting cylinder portion 77 extending rearward and inward in the vehicle width direction. The mounting cylinder portion 77 has a large diameter portion 77a having a step portion 77b interposed between a large diameter cylinder portion 77a having one end opened rearward and inward in the vehicle width direction and the other end of the large diameter cylinder portion 77a. A small-diameter tubular portion 77c coaxially connected to the tubular portion 77a is provided, and a second accommodating tubular portion 46 included in the first cover member 48 in the actuator case 39 of the electric actuator 36 is formed by the large-diameter tubular portion 77a. A C-shaped retaining ring 79 mounted on the outer periphery of the second accommodating tubular portion 46 engages with the locking groove 78 inserted inside and formed on the inner circumference of the large-diameter tubular portion 77a. The actuator case 39 is attached to the mounting cylinder portion 77.

As described above, the actuator case 39 is attached to the mounting cylinder portion 77 of the back plate 13, so that the actuator case 39 is attached to the rear side of the back plate 13 in the vehicle front-rear direction, and the connector portion. The terminal 55 arranged on the 48b is directed to the rear side in the front-rear direction of the vehicle. Further, between the outer circumference of the small diameter cylinder portion 46b of the second accommodating cylinder portion 46 and the outer circumference of one end portion of the screw shaft 38, a bellows shape covering the protruding portion of the screw shaft 38 from the second accommodating cylinder portion 46. Boots 80 are provided.

Next, the operation of this embodiment will be described. The drum brake device 11 can obtain the parking brake state by pulling the brake cable 37 connected to the parking brake lever 34 by the electric actuator 36, and is electrically operated. The actuator 36 can satisfactorily control the operation and release of the parking brake.

Moreover, the cable guide 81 fixed to the back plate 13 of the drum brake device 11 and arranged in the back plate 13 has a guide portion 81a for guiding the brake cable 37 and the parking brake lever 34 in the parking brake state. Since the stopper 81b that comes into contact with the brake drum 14 and regulates the operating end of the parking brake lever 34 is integrally provided, the gap between the inner surface of the brake drum 14 and the first and second brake shoes 15 and 16 becomes wide. The excessive operating amount of the parking brake lever 34 at the time of parking braking is regulated by the parking brake lever 34 coming into contact with the stopper 81b, and the component member on the electric actuator 36 side, for example, the screw shaft 38. It is possible to prevent the screw shaft 38 from operating until it comes into contact with the closed end of the bottomed cylindrical guide cylinder portion 49a of the second cover member 49, for example. Moreover, since the operating amount of the parking brake lever 34 can be regulated on the drum brake side, it is not necessary to provide a stopper in the electric actuator 36, and the structure of the electric actuator 36 can be simplified.

Further, the cable guide 81 is attached to the back plate 13 together with the anchor block 21 while having a guide portion 81a for guiding the brake cable 37, and the stopper 81b is integrally provided on the cable guide 81. Therefore, a dedicated member for fulfilling the stopper function is not required, and it is possible to avoid an increase in the number of parts and processing man-hours and prevent the operating amount of the parking brake lever 34 from becoming excessive, and the drum brake device 11 The present invention can be satisfactorily applied to the vehicle.

Further, since the stopper 81b is configured to have elasticity, even if the parking brake lever 34 impacts the stopper 81b, the impact can be absorbed, and the constituent members on the electric actuator 36 side, for example, the screw shaft 38 and It is possible to prevent the nut 61 from being locked.

Further, the electric actuator 36 has a screw shaft 38 connected to a brake cable 37 connected to a parking brake lever 34 urged toward a non-operating position side, and a screw shaft 38 in the axial direction while blocking its rotation. The actuator case 39 that enables reciprocating motion, the electric motor 40 that is supported by the actuator case 39 so that it can rotate freely in the forward and reverse directions, and the nut 61 that meshes with the screw shaft 38 are provided as one component and described above. A motion conversion mechanism interposed between the electric motor 40 and the screw shaft 38 and housed in the actuator case 39 while making it possible to convert the rotary motion generated by the electric motor 40 into a linear motion of the screw shaft 38. The brake cable 37 is provided with 41, and the brake cable 37 is pulled so as to drive the parking brake lever 34 toward the operating position side, and the parking brake lever 34 is returned from the operating position to the non-operating position side. The loosening state can be switched by changing the rotation direction of the electric motor 40, but the screw shaft 38 is provided with a flange portion 38a protruding outward in the radial direction and opens toward the flange portion 38a side. The recess 70 is formed coaxially with the nut 61, and when the screw shaft 38 is moved to the side where the brake cable 37 is loosened, the flange portion 38a is interposed between the flange portion 38a and the nut 61 to form the nut. A countersunk spring 71 that exerts an elastic force that urges the side to be separated from the 61 is housed in the recess 70.

Therefore, the elastic force of the disc spring 71 acts on the screw shaft 38 when the screw shaft 38 is moved to the side where the brake cable 37 is loosened, whereby a load is applied to the electric motor 40 during the return operation. It becomes possible to give. Moreover, since the disc spring 71 is housed in the recess 70 formed in the nut 61 coaxially with the screw shaft 38, it is not necessary to secure an extra space for arranging the disc spring 71, and the actuator case 39 is compact. In addition, since the elastic force of the disc spring 71 acts on the actuator case 39 only during the parking brake, it is not necessary to increase the strength of the actuator case 39 more than necessary.

Further, since a plurality of stacked disc springs 71 are housed in the recess 70, the elastic load can be changed by selecting the number of disc springs 71, and the specifications can be changed according to the type of the electric actuator 36. Becomes easier.

Further, the flange portion 38a is formed so as to protrude outward from the screw shaft 38 in the radial direction in a direction along one diameter line of the screw shaft 38, and is formed on the actuator case 39 on the axis of the screw shaft 38. Since a pair of locking grooves 73 extending along the direction and engaging the flange portion 38a in a slidable manner are formed, it is possible to prevent the screw shaft 38 from rotating while allowing the screw shaft 38 to move in the axial direction. The structure for preventing the rotation of the screw shaft 38 can be simplified.

Further, since the electric actuator 36 is attached to the back plate 13 of the drum brake device 11, the present invention can be satisfactorily applied to the drum brake device 11.

Further, the actuator case 39 of the electric actuator 36 accommodates a first accommodating cylinder portion 45 for accommodating an electric motor 40 that exerts power for obtaining a parking brake state so that a part of the electric motor 40 faces the outside. The case main body 47, a lid portion 48a that covers the part of the electric motor 40 and is coupled to the first accommodating cylinder portion 45, and a terminal 55 connected to the electric motor 40 are arranged. A first cover member 48 having a connector portion 48b projecting laterally from the lid portion 48a and arranged sideways to the first accommodating cylinder portion 45 is provided, and the first cover member 48 is the said. Since it is possible to arbitrarily select the circumferential relative position of the connector portion 48b with respect to the first accommodating cylinder portion 45 at at least a plurality of locations and it is coupled to the first accommodating cylinder portion 45, it can be laid out for each vehicle type. It is not necessary to make the actuator case 39 at the same time, and the position of the connector portion 48b with respect to the actuator case 39 can be easily changed to give versatility, and the cost increase can be suppressed by making it compatible with various types of vehicles. Can be done.

Further, locking recesses 51 are formed at a plurality of locations spaced apart in the circumferential direction from the protruding end portion of the electric motor 40 from the first accommodating cylinder portion 45, and the lid portion 48a of the cover member 48 is covered with the above. Since a plurality of engaging protrusions 52 that engage with the locking recess 51 are provided, the relative positions of the lid portion 48a and the connector portion 48b with respect to the electric motor 40 in the circumferential direction can be fixedly determined.

Moreover, since the engaging protrusion 52 is formed in a U shape divided into two in the circumferential direction of the lid portion 48a so as to be elastically engaged with the locking recess 51, the cover member The lid portion and the electric drive source of the above are elastically engaged with each other, so that the electric motor 40 and the lid portion 48a can be more reliably engaged with each other. In particular, in this embodiment, a wave washer 56 is interposed between the electric motor 40 and the lid portion 48a, and the engaging protrusion 52 is elastically engaged with the locking recess 51. In cooperation with the elastic force exerted by the wave washer 56, the influence of vibration during operation of the electric motor 40 can be prevented from reaching the lid portion 48a as much as possible.

Further, since the connecting portion 57 of the first accommodating cylinder portion 45 and the lid portion 48a is formed so as to have a circular or regular polygonal cross-sectional shape, the degree of freedom in the position of the connector portion 48b with respect to the actuator case 39. Can be easily changed, and the orientation of the connector portion 48b can be easily changed.

Further, since the actuator case 39 with the connector portion 48b facing the rear side in the vehicle front-rear direction is attached to the rear side in the vehicle front-rear direction of the back plate 13 included in the drum brake device 11 for the rear wheels, it is arranged in the connector portion 48b. The terminal 55 to be provided faces the rear side in the front-rear direction of the vehicle, so that the maintainability of the connector portion 48b when mounted on the vehicle can be improved, and the terminal 55 of the connector portion 48b can be protected from flying stones generated when the vehicle is running.

Further, since the first cover member 48 is bonded or welded to the first accommodating cylinder portion 45, the number of parts is increased when the first cover member 48 is bonded to the first accommodating cylinder portion 45. The first cover member 48 can be reliably connected to the first accommodating cylinder portion 45 while the orientation of the connector portion 48b can be easily changed without increasing the number.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various design changes are made without departing from the present invention described in the claims. Is possible.

For example, in the above-described embodiment, the case where the electric motor 40 is used as the electric drive source has been described, but the solenoid can also be used as the electric drive source. Further, in the above-described embodiment, the locking recess 51 is formed at the protruding end portion of the motor case 53 from the first accommodating cylinder portion 45, and the engaging protrusion 52 is formed on the lid portion 48a of the first cover member 48. However, an engaging protrusion is provided at the protruding end of the motor case 53 from the first accommodating cylinder 45, and is locked to the lid 48a of the first cover member 48. A recess may be formed.

11 ... Drum brake device 13 ... Back plate 36 ... Electric actuator 39 ... Actuator case 40 ... Electric motor 45 that is an electric drive source ... Accommodating cylinder 47 ... Case main body 48・ ・ ・ Cover member 48a ・ ・ ・ Lid part 48b ・ ・ ・ Connector part 52 ・ ・ ・ Engaging protrusion 51 ・ ・ ・ Locking recess 55 ・ ・ ・ Terminal 57 ・ ・ ・ Joint part

Claims (7)

In a vehicle drum brake device in which the actuator case (39) of the electric actuator (36) that obtains the parking brake state during operation is attached to the back plate (13), the actuator case (39) sets the parking brake state. A case main body (47) having a housing cylinder portion (45) for accommodating an electric drive source (40) that exerts power for obtaining the electric drive source (40) so that a part of the electric drive source (40) faces the outside, and the above. A lid portion (48a) that covers the part of the electric drive source (40) and is coupled to the storage cylinder portion (45) and a terminal (55) that is connected to the electric drive source (40) are arranged. The cover member (48) is provided with a cover member (48) integrally having a connector portion (48b) that projects laterally from the lid portion (48a) and is arranged on the side of the storage cylinder portion (45). ) Is coupled to the accommodating cylinder (45) so that the circumferential relative position of the connector (48b) with respect to the accommodating cylinder (45) can be arbitrarily selected at at least a plurality of locations. Drum brake device for vehicles. A plurality of locking recesses (51) are formed in one of the protruding end portion of the electric drive source (40) from the accommodating cylinder portion (45) and the lid portion (48a) of the cover member (48). A plurality of engaging with the locking recess (51) on the other side of the protruding end portion of the electric drive source (40) from the accommodating cylinder portion (45) and the lid portion (48a) of the cover member (48). The vehicle drum brake device according to claim 1, wherein the engaging protrusion (52) of the above is projected. The engaging protrusion (52) is formed in a U shape divided into two in the circumferential direction of the lid (48a) so as to be elastically engaged with the locking recess (51). The vehicle drum brake device according to claim 2. Any of claims 1 to 3, wherein the joint portion (57) of the accommodating cylinder portion (45) and the lid portion (48a) is formed so as to have a circular or regular polygonal cross-sectional shape. The vehicle drum brake device according to item 1. The actuator case (39) with the terminal (55) arranged on the connector portion (48b) facing the rear side in the vehicle front-rear direction is attached to the rear side of the back plate (13) of the rear wheel in the vehicle front-rear direction. The vehicle drum brake device according to any one of claims 1 to 4.
The vehicle drum brake device according to any one of claims 1 to 5, wherein the cover member (48) is bonded or welded to the housing cylinder portion (45). The vehicle drum brake device according to any one of claims 1 to 6, wherein the electric drive source is an electric motor (40).

Images