JP2009115155A - Disc brake device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a disc brake device that allows simplification of a configuration relating to a radial rotation stop of both piston plates on the driven side with respect to a rotary shaft without deteriorating transmission efficiency. <P>SOLUTION: The disc brake device includes a piston plate 24 on the drive side, piston plates 23, 25 on the driven side provided movably in the thrust direction with respect to a rotary shaft 15 with the piston plate 24 therebetween, a camshaft 50 for rotating the piston plate 24 on the drive side in the radial direction with respect to the rotary shaft 15 by its rotation, and a cam mechanism that allows the piston plates 23, 25 to be expanded in the thrust direction by the radial rotation of the piston plate 24 with respect to the rotary shaft 15. The piston plate 24 includes a pin 41 for receiving a force acting thereon during rotation of the camshaft 50. A pin 45 is provided in the piston plates 23, 25 in a hanging manner oppositely to the pin 41 with the camshaft 50 therebetween so as to receive a reaction force of the force, acting on the piston plate 24, via the camshaft 50. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a mechanical disc brake device installed in industrial vehicles, automobiles and the like.

  For example, some wet disc brake devices equipped on industrial vehicles such as forklifts are conventionally provided with two piston plates. In the disc brake device, when the camshaft is rotated in conjunction with the brake operation, one piston plate is rotated in the radial direction with respect to the rotation shaft, so that the cam mechanism provided between the piston plates. Thus, both piston plates are expanded in the thrust direction with respect to the rotation shaft, so that a braking force is generated on the brake disk on the rotation shaft. In addition, a general cam mechanism is comprised from the cam groove | channel formed in the opposing surface of both piston plates, respectively, and the ball interposed between the cam grooves.

  A disc brake device having three piston plates has also been proposed (see, for example, Patent Document 1). In this disc brake device, when the camshaft is rotated in conjunction with the brake operation, the drive-side piston plate located in the middle is rotated in the radial direction with respect to the rotation shaft, so that the piston plates adjacent to each other A configuration in which a braking force is generated on a brake disk on the rotating shaft by expanding both driven piston plates located on both sides in a thrust direction with respect to the rotating shaft via a cam mechanism provided between them. It has become.

JP-A-54-25372

  According to the disc brake device including the two piston plates, during braking, the piston plate is rotated between the piston plate and the brake housing and between the other piston plate and the brake disc with respect to the rotation axis of the piston plate. Friction with radial rotation is generated. The frictional force becomes a loss when the rotational torque of the camshaft is converted into the pressing force of both piston plates, and hence the transmission efficiency (hereinafter referred to as “transmission efficiency”) related to the conversion is inevitably lowered. There was a problem.

  Further, according to the disc brake device including the three piston plates, the driving side piston plate rotates in the radial direction with respect to the rotating shaft during braking, but the driven side piston plates are in the radial direction with respect to the rotating shaft. Since there is no rotation, there is friction between the brake housing and the driven piston plate and between the brake disk and the driven piston plate due to the rotation of the driven piston plate in the radial direction with respect to the rotation axis. Since it does not occur, the problem of reduced transmission efficiency is solved. However, since both the piston plates on the driven side with respect to the brake housing are individually assembled in a state that prevents rotation in the radial direction with respect to the rotation shaft, the configuration related to the rotation prevention of both the piston plates on the driven side is complicated. There was a problem to do.

  The problem to be solved by the present invention is to provide a disc brake device capable of simplifying the configuration relating to the rotation prevention in the radial direction with respect to the rotation shafts of both driven piston plates without lowering the transmission efficiency. It is in.

The above-described problem can be solved by a disc brake device having the gist of the configuration described in the appended claims.
That is, according to the disk brake device described in claim 1 of the claims, when the camshaft is rotated in conjunction with the brake operation, the drive-side piston plate is rotated in the radial direction with respect to the rotation shaft. The As a result, both the driven piston plates are expanded in the thrust direction with respect to the rotating shaft via the cam mechanism provided between the adjacent piston plates, so that the braking force is applied to the brake disk on the rotating shaft. Generated. Therefore, at the time of braking, although the drive side piston plate rotates in the radial direction with respect to the rotation axis, both driven side piston plates do not rotate in the radial direction with respect to the rotation axis. There is no friction between the brake disc and the driven piston plate due to the rotation of the driven piston plate in the radial direction with respect to the rotation axis, so the transmission efficiency does not decrease.
The first contact member provided on the drive side piston plate receives a force acting when the camshaft rotates, and the second contact member provided on both driven side piston plates serves as the drive side piston. The reaction force of the force acting on the plate is received via the camshaft. Therefore, the second abutting members provided on both driven piston plates abut against the camshaft, so that both driven piston plates are prevented from rotating in the radial direction with respect to the rotation shaft. For this reason, the structure which concerns on the rotation direction of the radial direction with respect to the rotating shaft of both piston plates of a driven side can be simplified.
Therefore, it is possible to simplify the configuration related to the rotation prevention in the radial direction with respect to the rotation shafts of the driven-side piston plates without reducing the transmission efficiency.

  According to the disc brake device recited in claim 2, the camshaft is arranged on a straight line extending in the radial direction of the drive-side piston plate, so that the camshaft is in the first contact state. Since it can be made to intervene easily between a member and the 2nd contact member, the assembly nature of a camshaft can be improved.

  According to the disc brake device recited in claim 3 of the claims, the first abutting member and the second abutting member are constituted by pins that are parallel to each other, so that the drive side While improving the assembly property of the 1st contact member with respect to a piston plate and improving the assembly property of the 2nd contact member with respect to both piston plates of a driven side, the both piston plates are connected easily. be able to.

  Next, the best mode for carrying out the present invention will be described with reference to examples.

An embodiment of the present invention will be described. In this embodiment, a wet type disc brake device for a battery-type forklift is illustrated. FIG. 1 is a sectional view showing the disc brake device.
As shown in FIG. 1, the disc brake device 10 is assembled between a pair of left and right motor housings 12 and 13 coupled to each other. A rotating shaft 15 is rotatably supported on the opposite end portions of the motor housings 12 and 13 on the same axis. Each rotary shaft 15 is directly connected to motor output shafts of left and right motors driven by a battery for generating a driving force of a forklift (not shown). The forklift is driven by rotating the wheels by the rotation of the rotary shafts 15.

  Cylindrical brake housing forming portions 12a and 13a that are connected in series to each other extend from opposite ends of the motor housings 12 and 13, respectively. On the base end side of both brake housing forming portions 12a and 13a, annular partition walls 12b and 13b projecting to the inner peripheral surface are formed. The rotating shaft 15 is rotatably supported by both partition walls 12b and 13b via bearings 16, respectively. Between both the partition walls 12b and 13b and the rotary shaft 15, oil seals 17 are provided for sealing between the two. The brake housing 18 of the disc brake device 10 is configured by the brake housing forming portions 12a and 13a of the motor housings 12 and 13 and the partition walls 12b and 13b.

  The left brake housing forming portion 12a is formed with a longer axial length (the length in the left-right direction in FIG. 1), and the right brake housing forming portion 13a is formed with a shorter axial length. ing. In addition, spline shafts 20 are integrally coupled to both the rotating shafts 15 protruding into the brake housing 18 in a state where the spline shafts 20 are externally fitted. In FIG. 1, the left spline shaft 20 is formed in a cylindrical shape extending rightward from the rotation shaft 15, and the right spline shaft 20 is provided on the rotation shaft 15, and the left spline shaft It is in parallel with the tip of the shaft 20 (the right end in FIG. 1).

  On both the spline shafts 20, two brake discs 21 arranged on the left and right are movable in the thrust direction (left and right direction in FIG. 1) with respect to the rotary shaft 15 by spline fitting, respectively, and in the radial direction with respect to the rotary shaft 15. It is provided so as to be integrally rotatable in the (circumferential direction). Further, the right brake disc 21 faces the partition wall 13b of the right motor housing 13 so as to come into surface contact. The brake disk 21 is not limited to one for each spline shaft 20, and a plurality of brake disks 21 may be provided as a set.

  In a space formed between the left brake disc 21 in the brake housing 18 and the partition wall 12b of the left motor housing 12 facing the brake disc 21, three piston plates having an annular plate shape are formed. 23, 24 and 25 are accommodated. These piston plates 23, 24, and 25 are overlapped in the left-right direction, and the left spline shaft 20 is inserted into a series of hollow holes. The left piston plate 23 faces the partition wall 12b of the left motor housing 12 so as to be in contact with the surface, and the right piston plate 25 faces the left brake disc 21 so as to be in contact with the surface. ing. It should be noted that at least one of the opposing surfaces of the brake discs 21, the opposing surface of the right brake disc 21 and the partition wall 13b of the right motor housing 13, and the opposing surface of the left brake disc 21 and the right piston plate 25 is provided. The friction material 26 is stuck.

  Between the piston plates 23, 24 and 25, that is, between the left piston plate 23 and the central piston plate 24, and between the central piston plate 24 and the right piston plate 25 will be described below. A cam mechanism is arranged. 2 is a side view showing the relationship between the piston plate and the camshaft, FIG. 3 is a sectional view taken along line III-III in FIG. 2, and FIG. 4 is a sectional view taken along line IV-IV in FIG. Further, in the operation related to the cam mechanism, the piston plate 24 located in the center corresponds to the driving side, and the piston plates 23 and 25 located on both sides thereof correspond to the driven side.

  As shown in FIG. 4, a cam mechanism 27 is disposed symmetrically between the piston plates 23, 24 and 25. A plurality of sets (three sets are shown in FIG. 2) of the cam mechanisms 27 are arranged at substantially equal intervals in the circumferential direction of the piston plates 23, 24, 25. Further, as shown in FIG. 4, the cam mechanism 27 is formed on the side surface of the drive side piston plate 24 and the side surface of the driven side piston plate 23 (or 25) opposed to the cam groove 28. And a ball 30 made of an iron ball or the like fitted so as to be able to roll between the cam grooves 28 and 29 facing each other. Both cam grooves 28 and 29 have arc groove shapes in the radial cross section of the piston plates 23, 24 and 25. The cam grooves 28 and 29 have a groove depth and a groove width that change in the circumferential direction of the piston plates 23, 24, and 25. That is, the cam grooves 28 and 29 are formed such that the direction in which the groove depth and the groove width gradually increase is opposite to the direction in which the groove depth and the groove width gradually decrease.

  The inclination angles θ1 and θ2 of the groove bottom surfaces 28a and 29a of the cam grooves 28 and 29 are set to the same angle (for example, 30 °), and the groove bottom surfaces 28a and 29a are parallel to each other. Therefore, the drive-side piston plate 24 moves or rotates in the direction in which the groove depth and groove width of both cam grooves 28 and 29 decrease (see arrow Y1 in FIG. 4), whereby both cam grooves 28 and 29 are moved. When the ball 30 rolls in the same direction, both piston plates 23 and 25 on the driven side move in the opposite direction, that is, expand in the thrust direction with respect to the rotating shaft 15 (see arrow Y2 in FIG. 4). The A braking force is generated on the brake disc 21 (see FIG. 1) by the expansion of the piston plates 23 and 25 in the thrust direction with respect to the rotating shaft 15.

  As shown in FIG. 3, a return spring 32 made of a coil spring is interposed between the outer peripheral portions of the driven piston plates 23 and 25. A plurality of return springs 32 (two are shown in FIG. 2) are arranged at substantially equal intervals in the circumferential direction of both piston plates 23 and 25. Further, the return spring 32 always urges the piston plates 23 and 25 in a direction to draw them. That is, the return spring 32 elastically holds the driven-side piston plates 23 and 25 at a position approaching each other (referred to as a “neutral position”). For this reason, the driven piston plates 23 and 25 expanded by the rotation of the driving piston plate 24 are caused by the elastic restoring force of the return spring 32 when the rotational force with respect to the piston plate 24 is released. Return to neutral position.

  A notch-shaped recess 34 is formed in the outer peripheral portion (the upper end portion in FIG. 2) of the drive-side piston plate 24. The side wall 35 on the rotational direction side (the upper side in FIG. 3) of the driving side piston plate 24 in the recess 34 is thickened. Further, as shown in FIG. 3, the side plate portions 23a, 25a of the driven side piston plates 23, 25 corresponding to the side wall portion 35 are respectively provided with concave surfaces 38 that are symmetrical on the side surfaces facing the side wall portion 35. It is thinned by being formed. Further, a pair of left and right support wall portions projecting in the opposite direction (lower side in FIG. 3) of the rotation direction (see arrow Y1 in FIG. 3) are provided on the left and right side portions of the side wall portion 35 of the drive side piston plate 24. 40 is formed. A first pin 41 made up of a headed pin is installed on both support wall portions 40. That is, the first pin 41 is inserted into a pin hole (not shown) formed in both support wall portions 40 and is prevented from being detached by the snap ring 42. Further, a flat surface 41a is formed on the side surface of the first pin 41 so as to be parallel to the surface including the center line of the pin 41 (see FIG. 2). The first pin 41 corresponds to a “first contact member” in this specification.

  As shown in FIG. 3, a second pin 45 is installed on the side plate portions 23a, 25a of the driven piston plates 23, 25. That is, the second pin 45 is inserted into a pin hole (reference numeral omitted) formed in the both side plate portions 23 a and 25 a and is prevented from being detached by the snap ring 46. The second pin 45 is disposed on the opposite side (lower side in FIG. 3) of the piston plate 24 in the recess 34 of the drive side piston plate 24 in the direction of rotation of the piston plate 24 (see arrow Y1 in FIG. 3). Has been. Further, a flat surface 45 a is formed on the side surface of the second pin 45 so as to be parallel to the surface including the center line of the pin 45. The second pin 45 corresponds to a “second contact member” in this specification.

  As shown in FIG. 1, a bearing hole 48 is formed at the upper end of the brake housing 18 (specifically, the brake housing forming portion 12a of the left motor housing 12). The bearing hole 48 is formed on a straight line L1 that extends in the radial direction of the piston plate 24 on the driving side and passes between the pins 41 and 45 (see FIG. 2). Further, the camshaft 50 is supported in the bearing hole 48 so as to be rotatable around the axis (straight line L1) in a state where the camshaft 50 is inserted from the outside of the brake housing 18 (upward in FIG. 1). The camshaft 50 is prevented from coming off by a retaining ring 51 fastened to the outer end portion (upper end portion in FIG. 1) of the bearing hole 48. A brake arm 53 is coupled to an upper end portion of the camshaft 50 that protrudes outside the brake housing 18. The brake arm 53 is linked to a brake pedal and a parking brake lever (not shown) via an interlocking mechanism such as a link mechanism. The brake arm 53 is linked to an operation of the brake pedal or the parking brake lever (referred to as “brake operation”). It is turned in the turning direction (see arrow Y3 in FIG. 3).

  A cylindrical cam portion 55 intervening between the pins 41 and 45 is formed at the lower end portion of the camshaft 50 projecting inward of the brake housing 18 (see FIG. 2). As shown in FIG. 3, the cam portion 55 is formed with a cam surface 56 formed of a flat surface parallel to a surface including the axis (straight line L1). When the brake operation is not performed, the cam surface 56 faces the flat surface 41a of the first pin 41 so as to be in contact with the surface. Further, the cylindrical outer peripheral surface 57 other than the cam surface 56 of the cam portion 55 is close to or in contact with the flat surface 45 a of the second pin 45. When the camshaft 50 is rotated in a predetermined rotation direction (see arrow Y3 in FIG. 3) by the brake operation, the cam surface 56 of the cam portion 55 abuts against the flat surface 41a of the first pin 41 and the same. By pushing the pin 41, the drive-side piston plate 24 is rotated in the radial direction with respect to the rotary shaft 15 (see arrow Y1 in FIG. 3).

  Next, the operation of the disc brake device 10 will be described. When the brake operation is not performed, the cam surface 56 of the cam portion 55 of the camshaft 50 faces the flat surface 41a of the first pin 41 so as to come into surface contact with the outer periphery of the cam portion 55. The surface 57 is close to or in contact with the flat surface 45a of the second pin 45 (see FIG. 3). At this time, both the driven piston plates 23 and 25 are held close to each other by the urging force of the return spring 32 with the driving piston plate 24 therebetween. Further, in the cam mechanism 27, the ball 30 is located in a portion where both the cam grooves 28 and 29 are deep (see FIG. 4). In this state, no braking force is applied to the brake disc 21.

  When a brake operation is performed from this state, the camshaft 50 is rotated in the direction of the arrow Y3 in FIG. As a result, the cam surface 56 of the cam portion 55 of the camshaft 50 abuts against the flat surface 41 a of the first pin 41 and pushes the pin 41, so that the piston plate 24 on the driving side is radial with respect to the rotating shaft 15. It is rotated in the direction (see arrow Y1 in FIG. 3). At this time, the reaction force of the force acting on the drive-side piston plate 24 acts on the camshaft 50, and the outer peripheral surface 57 of the cam portion 55 of the camshaft 50 and the flat surface 45a of the second pin 45 abut. Thus, it is received by the second pin 45.

  When the drive-side piston plate 24 is rotated in a radial direction with respect to the rotary shaft 15 (see arrow Y1 in FIG. 4), the balls 30 are in the same direction between the cam grooves 28 and 29 in the cam mechanisms 27. Roll to. Thereby, both the piston plates 23 and 25 on the driven side are expanded in the thrust direction (see arrow Y2 in FIG. 4) with respect to the rotating shaft 15 against the bias of the return spring 32 (see FIG. 3). . At this time, the piston plates 23 and 25 do not rotate in the radial direction with respect to the rotating shaft 15 (a small amount of rotation is ignored).

  As the driven piston plates 23 and 25 expand, the left driven piston plate 23 comes into contact with the partition wall 13b of the right motor housing 13 in a surface contact manner, and the piston plate 23 moves to the left. Movement is restricted (see FIG. 1). Accordingly, the drive-side piston plate 24 and the other driven-side piston plate 25 move rightward in FIG. 1, so that the right-side driven-side piston plate 25 moves both brake discs 21 to the right-side motor housing 13. To the partition wall 13b. As a result, a braking force is generated in the brake disk 21 due to the frictional force generated when the both brake discs 21 are sandwiched between the driven piston plate 25 and the partition wall 13b, and consequently the braking force is applied to both the rotary shafts 15. Is granted.

  Subsequently, when the brake operation force is released, the camshaft 50 is returned to the original position (see FIG. 3). On the other hand, both the piston plates 23 and 25 on the driven side are returned to the neutral position by the urging force of the return spring 32, and the ball 30 extends in a direction in which the groove depth between the cam grooves 28 and 29 in the cam mechanism 27 is deep. , The piston plate 24 on the driving side is returned to the original position in the radial direction with respect to the rotating shaft 15 and rotated (see FIG. 4). Also at this time, the driven piston plates 23 and 25 do not rotate in the radial direction with respect to the rotating shaft 15 (a small amount of rotation is ignored). Along with this, the force to sandwich the brake disk 21 between the right driven piston plate 25 and the partition wall 13b of the right motor housing 13 is released. For this reason, the braking force with respect to the brake disk 21 is lost, and as a result, both rotary shafts 15 can rotate.

  According to the disc brake device 10, when the camshaft 50 is rotated in conjunction with the brake operation, the drive-side piston plate 24 is rotated in the radial direction with respect to the rotating shaft 15. Thereby, both the piston plates 23 and 25 on the driven side are expanded in the thrust direction with respect to the rotating shaft 15 through the cam mechanism 27 provided between the piston plates 23 and 24 and 23 and 25 adjacent to each other. Thus, a braking force is generated on the brake disc 21 on the rotating shaft 15. Therefore, at the time of braking, although the piston plate 24 on the driving side rotates in the radial direction with respect to the rotating shaft 15, both the piston plates 23 and 25 on the driven side do not rotate in the radial direction with respect to the rotating shaft 15. With the rotation of the driven piston plates 23 and 25 in the radial direction between the left driven piston plate 23 and between the brake disk 21 and the right driven piston plate 25 with respect to the rotation axis. Since friction does not occur, transmission efficiency does not decrease. In other words, the rotational torque of the camshaft 50 for generating the necessary braking force can be reduced.

  In addition, the first pin 41 provided on the driving-side piston plate 24 receives a force acting when the camshaft 50 rotates, and the second pin 45 provided on both the driven-side piston plates 23 and 25 is driven. The reaction force of the force acting on the side piston plate 24 is received via the camshaft 50. Therefore, the second pins 45 provided on the driven piston plates 23 and 25 abut against the camshaft 50, so that the driven piston plates 23 and 25 are prevented from rotating in the radial direction with respect to the rotary shaft 15. . For this reason, the rotation prevention of the radial direction with respect to the rotating shaft 15 of the piston plates 23 and 25 of the driven side with respect to the brake housing 18 is abbreviate | omitted, and the structure concerning the rotation prevention can be simplified.

  Further, by arranging the camshaft 50 on a straight line L1 extending in the radial direction of the piston plate 24 on the driving side, the camshaft 50 (specifically, the cam portion 55) is placed on the first pin 41 and the second pin 45. Therefore, the camshaft 50 can be easily assembled.

  Further, since the first contact member and the second contact member are configured by the pins 41 and 45 that are parallel to each other, the first contact member (first pin with respect to the piston plate 24 on the driving side). 41) while improving the assembling property of the second abutting member (second pin 45) with respect to the driven piston plates 23, 25, while improving the assembling property of 41). Can be easily connected.

  The present invention is not limited to the above-described embodiments, and modifications can be made without departing from the gist of the present invention. For example, in the above-described embodiment, the wet type disc brake device of the battery type forklift is illustrated, but the present invention can be applied to disc brake devices of industrial vehicles, automobiles, etc. other than the battery type forklift. Moreover, in the said Example, although the disc brake apparatus 10 which brakes the right and left rotating shaft 15 simultaneously was illustrated, this invention is also applicable to the disc brake apparatus which brakes one rotating shaft. Further, the inclination angles θ1 and θ2 (see FIG. 4) of the groove bottom surfaces 28a and 29a of both the cam grooves 28 and 29 are set to the same angle in the above embodiment, but different angles, for example, one inclination angle is 20 °. The other inclination angle may be 10 °. Further, the first contact member and / or the second contact member are not limited to the pins 41 and 45, and may be members that receive a force applied from the cam portion 55 of the cam shaft 50. The first pin 41 and / or the second pin 45 may be a round shaft pin that does not have the flat surfaces 41a and 45a.

1 is a cross-sectional view showing a disc brake device according to an embodiment of the present invention. It is a side view which shows the relationship between a piston plate and a cam shaft. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. FIG. 4 is a sectional view taken along the line IV-IV in FIG. 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Disc brake device 15 Rotating shaft 18 Brake housing 21 Brake disc 23 Drive side piston plate 24 Drive side piston plate 25 Drive side piston plate 27 Cam mechanism 41 1st pin (1st contact member)
45 Second pin (second contact member)
50 camshaft

Claims (3)

A brake housing in which a rotation shaft is rotatably provided;
A drive-side piston plate provided in the brake housing so as to be rotatable in a radial direction with respect to the rotation shaft;
Both driven-side piston plates provided so as to be movable in the thrust direction with respect to the rotating shaft with the driving-side piston plate interposed therebetween;
A camshaft rotated by a brake operation and rotating the drive-side piston plate in a radial direction with respect to the rotating shaft by the rotation;
A braking force is generated on the brake disk on the rotating shaft by expanding both the driven piston plates in the thrust direction with respect to the rotating shaft by rotating the piston plate on the driving side in the radial direction with respect to the rotating shaft. With a cam mechanism,
A first abutting member that receives a force acting when the camshaft rotates is provided on the piston plate on the driving side,
The second piston plate on the driven side is opposed to the first abutting member between the cam shafts and receives a reaction force acting on the piston plate on the driving side via the cam shaft. A disc brake device characterized in that two contact members are installed. The disc brake device according to claim 1,
The disc brake device according to claim 1, wherein the camshaft is arranged on a straight line extending in a radial direction of the piston plate on the driving side. The disc brake device according to claim 1 or 2,
The disc brake device according to claim 1, wherein the first abutting member and the second abutting member are configured by pins parallel to each other.

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