JP2009191916A - Driving force transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving force transmission device with a pressure control function, having reduced cost and a reduced dimension. <P>SOLUTION: A protruded portion 153a1 for restricting the turn of a piston body 153a is arranged in opposition to a breather hole 65a2 to prevent the breather hole 65a2 from being completely exposed into a space covered with a side cover 66a. Thus, the protruded portion 153a1 functions as a plate for interrupting the communication of the breather hole 65a2. Namely, the protruded portion 153a1 functions in the side cover 66a, as a baffle plate for suppressing the flow of oil which lubricates a driving force adjusting part 100a, out of the breather hole 65a2 to the outside. This eliminates the need for a plate to cover the breather hole 65a2 and for a space in which the plate is mounted, thus reducing cost and reducing the weight and dimension. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a driving force transmission device, and more particularly to a driving force transmission device having a pressure adjustment function capable of reducing cost and size.

Conventionally, a breather hole that connects the inside and outside of the case is formed on the inner wall of the case where the rotating shaft, clutch mechanism, etc. are arranged, and the air breather function (hereinafter referred to as “pressure adjustment function”) There is known a transfer device (hereinafter referred to as “driving force transmission device”). In this driving force transmission device, a plate-like plate or the like is disposed at a position facing the breather hole in order to prevent the lubricating oil of the clutch mechanism from flowing out of the breather hole (see, for example, Patent Document 1). .
Japanese Utility Model Publication No. 3-108531

  However, in the driving force transmission device having a pressure adjusting function in which a plate is arranged at a position opposite to the breather hole, a plate as a separate part is attached in the case, so that the cost is increased and the plate is attached in the case. Since extra space was required, there was a problem that it was not possible to reduce the scale. Further, when the plate is integrally formed with the case, the shape becomes complicated, so that there is a problem that the yield is lowered and the cost is increased.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a driving force transmission device having a pressure adjusting function capable of reducing the cost and the scale.

  In order to achieve this object, a driving force transmission device according to claim 1 includes a prime mover that generates a driving force, an input shaft to which the driving force generated by the prime mover is input, and a drive that is input to the input shaft. A transmission mechanism that transmits force to the output shaft and a cover that covers the transmission mechanism, and has a pressure adjustment function that adjusts the pressure in the cover. And a clutch mechanism that can intermittently output the driving force input to the input shaft to the output shaft, and the clutch mechanism to output the driving force input to the input shaft to the output shaft. A piston that generates a pressing force for transition by an extension operation, a protruding piece that protrudes outward from the outer edge portion of the piston, and an intermediate member that is fixed along the outer edge portion of the piston and is inserted with the protruding piece It has an insertion part A restricting member for restricting the rotation of the protruding piece by the insertion part, formed on a portion corresponding to the insertion part of the restriction member on the inner wall of the cover member, The communication hole which connects is provided.

  The driving force transmission device according to claim 2 is the driving force transmission device according to claim 1, wherein the communication hole is positioned at a substantially center of the insertion portion in a first direction corresponding to a rotation direction of the output shaft. And the length in the said 1st direction is formed in the said protrusion piece more than half the width | variety of the said insertion part in the 1st direction.

  The driving force transmission device according to claim 3 is the driving force transmission device according to claim 1 or 2, wherein the insertion portion, the protruding piece, and the communication hole are separated from a vertical line passing through the axis of the output shaft. The position is located above the output shaft.

  The driving force transmission device according to claim 4 is the driving force transmission device according to any one of claims 1 to 3, wherein the cover includes at least a piston housing portion that houses at least an end portion of the piston on the side opposite to the clutch mechanism. The projection piece is formed at an end portion on the clutch mechanism side and is located outside the piston housing portion.

  The driving force transmission device according to claim 5 is the driving force transmission device according to claim 4, further comprising a pressing member that transmits the pressing force generated by the extension operation of the piston to the clutch mechanism. It is formed in a cylindrical shape, and is configured such that the distance from the axis of the output shaft to the maximum diameter is longer than the distance from the axis of the output shaft to the farthest position of the pressing member. .

  According to the driving force transmission device of the first aspect, the driving force generated by the prime mover is input to the input shaft, and the driving force input to the input shaft is transmitted to the output shaft by the transmission mechanism. The transmission mechanism is connected to the shaft center portion of the clutch mechanism when the clutch mechanism is shifted to a state in which the driving force input to the input shaft is output to the output shaft by the pressing force generated by the extension operation of the piston. The driving force is transmitted to the output shaft. In addition, a restricting member is fixed along the outer peripheral portion of the piston, and a protruding piece that protrudes outward from the outer edge portion of the piston is inserted into the interposed portion of the restricting member, and the inserted portion The rotation of the protruding piece is restricted. That is, when the piston is extended, even if the piston is dragged in the rotation direction as the clutch mechanism rotates, the rotation of the piston can be regulated by the insertion portion and the protruding piece. There is.

  In addition, a communication hole that communicates the inside and the outside of the cover that covers the transmission mechanism is formed on the inner wall of the cover corresponding to the insertion portion of the restricting member, and the pressure in the cover is adjusted. (Pressure adjustment function). That is, since the communication hole for adjusting the pressure in the cover is located at a portion corresponding to the insertion portion of the restriction member, when the protruding piece of the piston is inserted into the insertion portion of the restriction member, the protrusion piece becomes the communication hole. Opposed. Therefore, the protruding piece for restricting the rotation of the piston acts as a member that blocks between the inside and the outside of the communication hole. This eliminates the need for a plate or the like for suppressing oil that lubricates the transmission mechanism from flowing out of the communication hole, and eliminates the need for a space for mounting the plate. There is an effect that can be done.

  According to the driving force transmission device of the second aspect, in addition to the effect exerted by the driving force transmission device of the first aspect, the communication hole is formed at substantially the center of the insertion portion in the first direction corresponding to the rotation direction of the output shaft. Is located, and the length of the protruding piece in the first direction is formed to be half or more of the width of the insertion part in the first direction. Therefore, even if the piston is dragged in the rotation direction with the rotation of the clutch mechanism and the protruding piece comes into contact with the end surface of the insertion portion, the protruding piece is always located at a position that obstructs the communication hole. Therefore, it is possible to prevent the communication hole from being completely exposed to the inside of the cover without being obstructed by the protruding piece.

  According to the driving force transmission device according to claim 3, in addition to the effect exerted by the driving force transmission device according to claim 1 or 2, the insertion portion, the protruding piece, and the communication hole are perpendicular to the axis of the output shaft. Since the position is off the line and above the output shaft, the insertion portion, the protruding piece, and the communication hole are disposed at a position inclined from the vertical line passing through the axis of the output shaft. Here, if an insertion part or a projecting piece is arranged on a vertical line passing through the axis of the output shaft and above the output shaft, the lubricating oil or the like adhering to the insertion part or the projecting piece is connected to the piston and the projecting piece. Therefore, the possibility of lubricating oil flowing out from the communication hole is increased. However, since the insertion portion, the protruding piece, and the communication hole are disposed at a position inclined from the vertical line passing through the axis of the output shaft, the lubricating oil or the like attached to the insertion portion or the protruding piece easily flows downward. . Therefore, there is an effect that it is possible to make it difficult for lubricating oil or the like to flow out of the communication hole.

  In general, the driving force transmission device is often attached to a moving body such as a vehicle. Therefore, if the communicating hole is inclined and formed on the forward side of the moving body, the lubricating oil in the case can easily move to the backward side of the moving body, and the lubricating oil moves in the direction away from the communicating hole in the case. Also, there is an effect that it is possible to efficiently suppress the outflow of lubricating oil or the like from the communication hole.

  According to the driving force transmission device of the fourth aspect, in addition to the effect exhibited by the driving force transmission device according to any one of the first to third aspects, at least the end portion of the piston on the side opposite to the clutch mechanism is formed in the case. A protruding piece that is housed in the piston housing part and formed at the end on the clutch mechanism side is located outside the piston housing part. Therefore, since the protruding piece is located outside the piston accommodating portion, a space for accommodating the protruding piece in the piston accommodating portion becomes unnecessary. Therefore, since it can suppress that the shape of a piston accommodating part is complicated, there exists an effect that it can suppress that the shape of a cover becomes complicated.

  According to the driving force transmission device according to claim 5, in addition to the effect of the driving force transmission device according to claim 4, the piston is formed in a substantially cylindrical shape, and the pressing force generated by the extension operation of the piston Is transmitted to the clutch mechanism through the pressing member. Further, since the distance from the shaft center of the output shaft of the piston to the maximum diameter is longer than the distance from the shaft center of the output shaft to the farthest position of the pressing member, the pressing force is supplied. The load is not applied to the protruding piece formed on the outer edge portion of the piston. Therefore, since it is not necessary to form the protruding piece extremely large and give it strength, there is an effect that the cost can be reduced and the scale can be reduced.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings. First, a four-wheel drive vehicle 1 on which driving force adjusting mechanisms 60a and 60b according to an embodiment of the present invention are mounted will be described with reference to FIG. The driving force adjustment mechanisms 60a and 60b according to the present embodiment distribute the driving force output from the prime mover 10 to the rear wheels 70a and 70b, respectively.

  FIG. 1 is a schematic diagram showing a four-wheel drive vehicle 1 on which driving force adjusting mechanisms 60a and 60b are mounted. An arrow X shown in FIG. 1 indicates the front-rear direction of the four-wheel drive vehicle 1, and an arrow Y indicates the left-right direction of the four-wheel drive vehicle 1.

  As shown in FIG. 1, a four-wheel drive vehicle 1 is an internal combustion engine that generates a driving force, and a driving force input from the driving device 10 via a connecting shaft 91 is changed by a transmission 21. An output transmission 20, and a front / rear driving force distribution device 30 that distributes the driving force input from the transmission 20 through the connection shaft 92 to the connection shaft 96 and the central drive shaft 94 by the front / rear driving force distribution device distribution unit 31; The front-wheel differential gear portion 32 that distributes the driving force distributed to the connecting shaft 96 by the front-rear driving force distribution device 30 to the front drive shafts 93a, 93b, and the front-wheel differential gear portion 32 distributes it to the front drive shafts 93a, 93b. The pair of front wheels 40a and 40b that rotate when the generated driving force is transmitted, and the front and rear driving force distribution device 3 , The driving force distributed to the central drive shaft 94 is transmitted, the driving force distribution mechanism 50 that distributes the transmitted driving force to the rear drive shafts 95a and 95b, and the rear drive shaft by the driving force distribution mechanism 50. The driving force adjusting mechanisms 60a and 60b for adjusting the ratio of the driving force distributed to 95a and 95b, and the driving force adjusted by the driving force adjusting mechanisms 60a and 60b to the rear drive shafts 95a and 95b, respectively, are transmitted. A pair of rear wheels 70a and 70b that rotate and a control device 80 that performs various controls of the driving force adjusting mechanisms 60a and 60b are configured. Note that the driving force distribution mechanism 50 and the driving force adjustment mechanisms 60 a and 60 b are rotatably fixed inside the case 61.

  The front wheel differential gear portion 32 is an operating device that distributes the driving force transmitted from the connecting shaft 96 to the front drive shafts 93a and 93b and distributes the rotational speed of the connecting shaft 96 to the front drive shafts 93a and 93b.

  The driving force distribution mechanism 50 includes an input gear unit 51 coupled to the central drive shaft 94 and an output gear unit 52 disposed in a direction orthogonal to the input gear unit 51 (the arrow Y direction in FIG. 1). Configured. Therefore, the driving force distribution mechanism 50 distributes the driving force input to the input gear unit 51 by the output gear unit 52, and the driving force disposed on the left and right (both sides in the Y direction in FIG. 1) of the driving force distribution mechanism 50. The driving force is distributed to the adjusting mechanisms 60a and 60b. A detailed description of the driving force distribution mechanism 50 will be described later with reference to FIG.

  The driving force adjusting mechanisms 60a and 60b are installed symmetrically on the left and right (in the direction of arrow Y in FIG. 1) of the driving force distributing mechanism 50, and are connected to both ends of the output gear unit 52, respectively. The driving force adjusting mechanisms 60a and 60b are the driving force adjusting mechanism 60a on the right side (right side in the arrow Y direction in FIG. 1) of the driving force distributing mechanism 50, and the left side (left side in the arrow Y direction in FIG. 1) of the driving force distributing mechanism 50. Is the driving force adjusting mechanism 60b.

  The driving force adjusting mechanism 60a includes a driving force adjusting unit 100a that adjusts transmission of driving force, an oil supply mechanism 200a that sends oil to the driving force adjusting unit 100a, and the hydraulic pressure of the oil that is pumped by the oil supplying mechanism 200a. And a pressure detection mechanism 300a for detection. The driving force adjusting unit 100a adjusts the transmitted driving force by the hydraulic pressure generated when the oil supply mechanism 200a sends out the oil. The hydraulic pressure is detected by the pressure detection mechanism 300a, and the detection result of the pressure detection mechanism 300a is input to the control device 80. The driving force adjustment mechanism 60b is configured in the same manner as the driving force adjustment mechanism 60a, and includes a driving force adjustment unit 100b, an oil supply mechanism 200b, and a pressure detection mechanism 300b. A detailed description of the driving force adjusting mechanisms 60a and 60b will be described later with reference to FIGS.

  The control device 80 includes an I / O port 83 to which input lines 81a and 81b from the pressure detection mechanisms 300a and 300b and output lines 82a and 82b to the oil supply mechanisms 200a and 200b are connected, and mainly hydraulic pressure information. , A pressure control program 87 for controlling the oil supply mechanisms 200a and 200b, a ROM 84 which is a storage device in which the pressure control program 87 is written, a CPU 85 which is an arithmetic device for calculating based on the pressure control program 87, and I The / O port 83, the ROM 84, and the CPU 85 are configured to include a bus line 86 that is a connection circuit that electrically connects the CPU 85. In the present embodiment, the control device 80 includes oil supply mechanisms 200a and 200b that supply oil necessary for the driving force adjusting units 100a and 100b to operate based on the detection results of the pressure detection mechanisms 300a and 300b. Individual feedback control.

  Next, with reference to FIG. 2, the appearance of the driving force adjusting mechanism 60b and the driving force distribution mechanism 50 will be described. FIG. 2 is an enlarged side view showing the driving force adjusting mechanism 60b and the driving force distribution mechanism 50. FIG. In addition, the arrow X shown in FIG. 2 has shown the front-back direction of the four-wheel drive vehicle 1, and the arrow Z has shown the up-down direction of the four-wheel drive vehicle 1. FIG.

  As described above, the driving force adjustment mechanism 60b includes the driving force adjustment unit 100b (see FIG. 1) that adjusts transmission of the driving force, the oil supply mechanism 200b that sends oil to the driving force adjustment unit 100b, and the oil supply mechanism. It has a pressure detection mechanism 300b (see FIG. 1) for detecting the hydraulic pressure of oil pumped from 200b.

  The oil supply mechanism 200b is outside the case 61 and is disposed below the driving force adjusting mechanism 60b (below the driving force adjusting mechanism 60b in the direction of arrow Z in FIG. 2). In addition, the oil supply mechanism 200b is configured such that the oil supplied to the driving force adjustment unit 100b by the oil supply mechanism 200b is discharged from the driving force adjustment unit 100b by natural fall and is accumulated in the oil supply mechanism 200b again. Yes. Furthermore, as will be described later, in the present embodiment, the oil supply chamber 200b is provided in the oil supply mechanism 200b (see FIG. 8), so that the oil storage chamber is the oil supply chamber as in the conventional automatic transmission and transfer case. Compared with the case where it is arranged below the supply mechanism 200b, the work of sucking up and storing the oil becomes unnecessary, and the efficiency of sending out the oil can be improved.

  As will be described later, since the driving force distribution mechanism 50 distributes the driving force using a hypoid gear, the rotation axis P of the driving force adjusting unit 100 and the rotation axis T of the driving force distribution mechanism 50 are extended. The line does not intersect.

  Next, detailed configurations of the driving force distribution mechanism 50 and the driving force adjustment mechanism 60a will be described with reference to FIGS.

  First, the configuration of the driving force distribution mechanism 50 and the schematic configuration of the driving force adjustment mechanisms 60a and 60b will be described with reference to FIGS. 3 is a cross-sectional view of the driving force distribution mechanism 50 and the driving force adjustment mechanisms 60a and 60b along the line III-III in FIG. 2, and FIG. 4 shows the driving force distribution mechanism 50 along the line IV-IV in FIG. It is sectional drawing of the driving force adjustment mechanism 60a, 60b. In FIGS. 3 and 4, the cross-sectional line is omitted. 3 and 4, the arrow X indicates the front-rear direction of the four-wheel drive vehicle 1 and indicates the direction of the rotational axis T of the drive force distribution mechanism 50, and the arrow Y indicates the left and right sides of the four-wheel drive vehicle 1. The direction Z indicates the direction of the rotational axis P of the driving force adjusting units 100a and 100b, and the arrow Z indicates the vertical direction of the four-wheel drive vehicle 1.

  First, the driving force distribution mechanism 50 will be described. As described above, the driving force distribution mechanism 50 changes the direction of the driving force transmitted by the central drive shaft 94 (see FIG. 1), and changes the driving force to the left and right of the four-wheel drive vehicle 1 (the direction of the arrow Y in FIG. 1). ) It distributes to the driving force adjusting mechanisms 60a and 60b arranged in each.

  As shown in FIGS. 3 and 4, the driving force distribution mechanism 50 has an input gear unit 51 to which the driving force transmitted by the central drive shaft 94 (see FIG. 1) is input, and the input gear unit 51. An output gear unit 52 that outputs the driving force input to the input gear unit 51 is disposed in the direction orthogonal to each other (the arrow Y direction in FIGS. 3 and 4).

  The input gear unit 51 is connected to the output gear unit 52 by fitting the hypoid gear 54 of the output gear unit 52 to the hypoid gear 53 of the input gear unit 51, and is transmitted by the central drive shaft 94 (see FIG. 1). The driving force is transmitted to the output gear unit 52.

  The output gear unit 52 has hub fitting portions disposed on the left and right sides of the output gear unit 52 (both sides in the Y direction in FIGS. 3 and 4) on output shaft spline portions 55 formed at both ends of the output gear unit 52. By fitting 103a, 103b, the driving force transmitted from the input gear unit 51 is distributed to the driving force adjusting mechanisms 60a, 60b.

  Therefore, in the driving force distribution mechanism 50, the input gear unit 51 and the output gear unit 52 are coupled by the hypoid gears 53 and 54, and the driving force adjustment is performed by the output shaft spline portion 55 and the hub fitting portions 103a and 103b. Since the mechanisms 60a and 60b are connected, the driving force input to the input gear unit 51 by the central drive shaft 94 (see FIG. 1) is adjusted to the driving force adjusting mechanisms 60a and 60b arranged on the left and right of the output gear unit 52. Can be distributed.

  The input gear unit 51 and the output gear unit 52 are rotatably fixed to the case 61 via a bearing b1. Therefore, the driving force input to the input gear unit 51 is not subjected to a large loss due to the sliding resistance between the input gear unit 51 and the case 61 and the sliding resistance between the output gear unit 52 and the case 61. Can be transmitted to the unit 52.

  Next, an outline of the configuration of the driving force adjusting mechanisms 60a and 60b will be described. As described above, the driving force adjusting mechanisms 60a and 60b are the driving force adjusting units 100a and 100b that adjust the transmission of the driving force, and the oil supply mechanisms 200a and 200b that send oil to the driving force adjusting units 100a and 100b (FIG. 4). Reference) and pressure detection mechanisms 300a and 300b (see FIG. 1) for detecting the hydraulic pressure of the oil sent out from the oil supply mechanisms 200a and 200b.

  Further, the driving force adjusting units 100a and 100b give the connection mechanisms 101a and 101b for adjusting the ratio of the driving force input by the output gear unit 52 of the driving force distribution mechanism 50 and the connection mechanisms 101a and 101b. Cam mechanisms 131a and 131b for amplifying the pressing force, piston mechanisms 151a and 151b for applying a pressing force to the cam mechanisms 131a and 131b, and a release for applying an urging force opposite to the piston mechanisms 151a and 151b to the cam mechanisms 131a and 131b It has mechanisms 171a and 171b.

  As shown in FIG. 4, the oil supply mechanisms 200a and 200b have electric motors 201a and 201b, and the electric motors 201a and 201b adjust the driving force and the axial center Q direction of the electric motors 201a and 201b. It arrange | positions so that the rotation axis P direction of the parts 100a and 100b may become substantially parallel (refer FIG.2 and FIG.4). Since the oil supply mechanisms 200a and 200b send oil discharged from the driving force adjusting units 100a and 100b to the driving force adjusting units 100a and 100b again, the oil supplying mechanisms 200a and 200b are below the driving force adjusting units 100a and 100b (see the arrow Z in FIG. 4). (Lower side).

  Here, since the driving force adjusting mechanisms 60a and 60b are located in the lower part of the four-wheel drive vehicle 1, it is preferable to make the thickness in the vertical direction (the arrow Z direction in FIG. 4) as small as possible from the viewpoint of the distance from the ground. Therefore, in the present embodiment, the electric motors 201a and 201b are integrally attached to the driving force adjusting mechanisms 60a and 60b, and the axis Q direction of the electric motors 201a and 201b is rotated by the driving force adjusting units 100a and 100b. As shown in the side view shown in FIG. 2, the electric motors 201a and 201b are disposed directly below the rotational axis P of the driving force adjusting mechanisms 60a and 60b (see FIG. 2). In the direction of the arrow Z passing through the rotation axis P in FIG. 5), the position of the driving force adjusting mechanisms 60a and 60b is prevented from becoming extremely large in the vertical direction.

  Next, the configuration of the case 61 will be described with reference to FIGS. FIG. 5 is a cross-sectional view of the case 61 taken along line IV-IV in FIG.

  As shown in FIG. 3 or 4, the driving force distribution mechanism 50 and the driving force adjustment units 100 a and 100 b are covered with a case 61, and the case 61 includes a center cover 65 that covers the driving force distribution mechanism 50, and It is comprised by the side covers 66a and 66b which cover the driving force adjustment parts 100a and 100b, and the retainer cover 67 located between the center cover 65 and the side cover 66b. The center cover 65, the side covers 66a and 66b, and the retainer cover 67 integrally cover the driving force distribution mechanism 50 and the driving force adjustment units 100a and 100b. That is, the case 61 includes four covers 65, 66a, 66b, and 67.

  As shown in FIG. 5, the center cover 65 is formed with a center holding portion 69 a that protrudes inward to hold the end of the output gear unit 52 on the driving force adjustment portion 100 a side, and the retainer cover 67 includes A retainer holding portion 69b protruding inward to hold the end of the output gear unit 52 on the driving force adjusting portion 100b side is formed. Further, the retainer cover 67 is formed in substantially the same shape as an end portion (a portion where the center holding portion 69a is formed) of the center cover 65 on the driving force adjusting portion 100a side. Therefore, it can be said that the retainer cover 67 is formed by dividing one end portion of the center cover having a holding portion for holding the output gear unit 52 at both end portions.

  The side cover 66a has six insertion holes 66a1 (six bolts are shown in FIG. 2) through which the bolts B are inserted, and the bolts B are inserted into the insertion holes 66a1. The side cover 66a is attached to the center cover 65 by being screwed into the screw groove 65a1 of the center cover 65. Similarly, six insertion holes 66b1 through which the bolts B are inserted are also formed in the side cover 66b, and the insertion holes 67b1 through which the bolts B are inserted into the retainer cover 67 at positions corresponding to the insertion holes 66b1. Is formed. The bolt B is inserted into the insertion holes 66b1 and 67b1 and screwed into the screw groove 65b1 of the center cover 65, and the side cover 66b and the retainer cover 67 are fastened together with the center cover 65.

  2, the side covers 66a and 66b are formed in a substantially cylindrical shape, and the insertion hole 66a1 of the side cover 66a, the insertion hole 66b1 of the side cover 66b, and the insertion hole 67b1 of the retainer cover 67 are Adjacent through holes 66a1, 66b1, and 67b1 are spaced apart by an angle a. That is, all the insertion holes 66a1, 66b1, and 67b1 are arranged at equal intervals in the circumferential direction. Furthermore, as can be seen from the cross-sectional view of FIG. 5, the side covers 66a and 66b are formed in the same shape. Therefore, since the side covers 66a and 66b can be made into common parts, the number of parts can be reduced and the cost can be reduced.

  Next, the motor covers 68a and 68b provided on the side covers 66a and 66b will be described. Motor covers 68a and 68b covering the electric motors 201a and 201b (see FIG. 4) are integrally formed on the side covers 66a and 66b. The motor covers 68a and 68b are formed in a substantially cylindrical shape having openings on the center cover 65 side and the anti-center cover 65 side. Therefore, since the electric motors 201a and 201b can be removed while the side covers 66a and 66b are attached to the center cover 65, maintenance workability is improved. Further, even if mud or water enters the motor covers 68a and 68b while the four-wheel drive vehicle 1 is running, the motor covers 68a and 68b are discharged from the opening. If necessary, mud and water can be easily taken out.

  Further, since the oil supply mechanisms 200a and 200b are arranged at positions substantially parallel to the rotational axis P direction of the driving force adjusting units 100a and 100b, by attaching the side covers 66a and 66b to the center cover 65, The electric motors 201a and 201b are also covered by the motor covers 68a and 68b. Therefore, compared with the case where the motor covers 67a and 67b are configured separately from the side covers 66a and 66b, the work of attaching a separate motor cover that covers the electric motors 201a and 201b can be omitted. Since an attachment portion for attaching the motor cover to the side covers 66a and 66b is not required, it is possible to achieve weight reduction, downsizing, and cost reduction.

  Even if the side covers 66a and 66b have a structure in which the motor covers 68a and 68b are provided, the insertion holes 66a1 and 66b1 are provided at substantially equal intervals and are formed in a cylindrical shape. 2 can be attached at the same position as the side cover 66b shown in FIG. 2 by shifting the insertion holes 66a1 and 66b1 by two with respect to the side cover 66b.

  Here, a procedure for assembling the driving force distribution mechanism 50, the driving force adjusting units 100a and 100b, and the case 61 will be briefly described. First, in the center cover 65, the input gear unit 51 and the output gear unit 52 are assembled (assembled with the hypoid gears 53, 54), and the tooth contact of each gear 53, 54 and the preload adjustment of the bearing b1 are performed. And while attaching the driving force adjustment part 100a to one end part of the output gear unit 52, the retainer cover 67 is temporarily fixed to the other end part of the output gear unit, and the driving force adjustment part 100b is attached. Thereafter, the oil supply mechanisms 200 a and 200 b (see FIG. 4) are attached to the center cover 65 and the retainer cover 67. The side cover 66a is attached to the center cover 65 so as to cover the driving force adjusting unit 100a, and the side cover 66a and the retainer cover 67 are fastened together with the center cover 65 so as to cover the driving force adjusting unit 100b. The force distribution mechanism 50, the driving force adjusting units 100a and 100b, and the case 61 are assembled.

  As described above, the center cover 65 is configured to be able to be opened by removing the retainer cover 67 on the side where the hypoid gear 54 is disposed on the driving force adjusting unit 100 b side. Therefore, when the input gear unit 51 and the output gear unit 52 are assembled in the center cover 65 and the tooth contact adjustment of the gears 53 and 54 is performed, the adjustment is easy and the work can be performed efficiently.

  Further, since the retainer cover 67 and the side cover 66b are fastened and fixed to the center cover 65 with the bolt B, the retainer cover 67 and the side cover 66b are individually attached to the center cover 65 as in the case of attaching the retainer cover 67 and the side cover 66b. The bolt B that attaches the cover 67 to the center cover 65 and the bolt B that attaches the side cover 66b to the center cover 65 do not interfere with each other. Therefore, since it is not necessary to provide the center cover 65 with an attachment portion for individually attaching the retainer cover 67 and the side cover 66b to the center cover 65, the center cover 65 can be prevented from being enlarged in scale. . As a result, it is possible to suppress an increase in the size of the transmission mechanism including the driving force distribution mechanism 50 and the driving force adjustment mechanisms 60a and 60b. Of course, since it is possible to suppress an increase in the scale of the driving force adjusting mechanisms 60a and 60b, it is possible to reduce the weight and the cost.

  Next, the driving force adjusting unit 100a of the driving force adjusting mechanism 60a among the driving force adjusting mechanisms 60a and 60b will be described with reference to FIGS. 6 and 7, the driving force adjusting unit 100a of the driving force adjusting mechanism 60a will be described. The driving force adjusting unit 100b of the driving force adjusting mechanism 60b is the driving force adjusting unit of the driving force adjusting mechanism 60a. Since the configuration is the same as that of 100a, detailed description thereof is omitted.

  FIG. 6 is an enlarged cross-sectional view of a portion A in FIG. 3 and shows a driving force adjusting unit 100a that is a part of the driving force adjusting mechanism 60a and a part of the case 61 (center cover 65 and side cover 66a). ing. 7A and 7B are diagrams schematically showing the cam mechanism 131a, FIG. 7A is a side view of the cam mechanism 131a, and FIG. 7B is a diagram of the cam mechanism 131a taken along line VIIb-VIIb in FIG. It is sectional drawing.

  Further, the arrow X shown in FIG. 6 indicates the front-rear direction of the four-wheel drive vehicle 1 and indicates the direction of the rotational axis T of the drive force distribution mechanism 50, and the arrow Y indicates the left-right direction of the four-wheel drive vehicle 1. 7 shows the direction of the rotational axis P of the driving force adjusting unit 100a of the driving force adjusting mechanism 60a, and the arrow R shown in FIG. 7 is centered on the rotational axis P of the driving force adjusting unit 100a of the driving force adjusting mechanism 60a. The circumferential direction (the vertical direction in FIG. 2) is shown.

  First, the connection mechanism 101a (see FIG. 3) of the driving force adjusting unit 100a will be described in detail. As shown in FIG. 6, the connection mechanism 101a includes a hub portion 102a to which a driving force transmitted from the output gear unit 52 is input, a substantially cylindrical clutch drum portion 105a coupled to the hub portion 102a, A plurality of drive plates 106a (seven in this embodiment) connected to the inside of the clutch drum portion 105a (in the direction toward the rotation axis P) and one drive plate 106a are alternately arranged between the drive plates 106a. Driven plates 107a (seven in this embodiment) and the plates arranged adjacent to the driven plates 107a and the drive plates 106a and arranged in parallel in the direction of the rotational axis P of the driving force adjusting unit 100a A clutch retainer 108a positioned on the outermost side (right side in the arrow Y direction) of 106a and 107a. .

  The hub portion 102 a is a member formed in a substantially annular shape, and is formed in a dish shape that is connected to the clutch drum portion 105 and a cylindrical portion 102 a 1 that is fitted into the output gear unit 52 and formed in a substantially cylindrical shape. And a dish-like portion 102a2. A hub fitting portion 103a is formed on a part of the inner surface of the tubular portion 102a1, and a spline joint is formed by the hub fitting portion 103a and the output shaft spline portion 55 of the output gear unit 52.

  A plurality of substantially trapezoidal hub protrusions 104a are formed at predetermined intervals in the circumferential direction on the outer surface (maximum diameter portion) of the dish-shaped portion 102a2, and are formed on the inner surface of the clutch drum portion 105a. A plurality of substantially trapezoidal drum groove portions 109a are formed at predetermined intervals in the circumferential direction. That is, the hub protrusion 104a and the drum groove 109a are formed so that a substantially trapezoidal convex portion and a concave portion are continuously formed in the circumferential direction. A spline joint is formed by the plurality of hub protrusions 104a and the plurality of drum grooves 109a. Therefore, the hub portion 102a can transmit the driving force transmitted from the output shaft spline portion 55 to the clutch drum portion 105a.

  As described above, in the present embodiment, the hub portion 102a and the clutch drum portion 105a are configured separately, and the driving force transmitted from the output shaft spline portion 55 is applied to the clutch drum portion 105a via the hub portion 120a. Communicating. The hub portion 102a is formed in a substantially conical shape by the cylindrical portion 102a1 and the dish-shaped portion 102a2, and the diameter of the cylindrical portion 102a1 is particularly small, so that the driving force from the output shaft spline portion 55 is transmitted. On the other hand, the clutch drum portion 105a has a larger diameter than the cylindrical portion 102a1 and is formed in a cylindrical shape, so that the material strength as high as that of the hub portion 102a is not required. Further, when the hub portion 102a and the clutch drum portion 105a are manufactured integrally, the structure becomes complicated and it is difficult to manufacture. For this reason, in the present embodiment, the hub portion 102a and the clutch drum portion 105a are configured as separate bodies so that the cost can be reduced without making all of them from a material having high material strength, and complicated production is required. The aim is to improve productivity.

  Further, the hub portion 102a is moved to the left side in the rotational axis P direction of the driving force adjusting portion 100 with respect to the clutch drum portion 105a (left side in the Y direction in FIG. 6) by the snap ring S3a fitted inside the clutch drum portion 105a. Movement is regulated.

  The clutch retainer 108a is a substantially disc-shaped plate, and, like the hub portion 102a, a plurality of substantially trapezoidal clutch retainer protrusions 115a formed on the outer edge of the clutch retainer 108a, and the inner surface of the clutch drum portion 105a. Spline joints are formed by a plurality of drum groove portions 109a each having a substantially trapezoidal shape, and are fitted into the clutch drum portion 105a. Further, the clutch retainer 108a is moved to the right side in the rotational axis P direction of the driving force adjusting portion 100a with respect to the clutch drum portion 105a by the snap ring S1a fitted in the clutch drum portion 105a (right side in the Y direction in FIG. 6). Is regulated.

  From the above, the force acting on the hub portion 102a from the right side in the rotational axis P direction of the driving force adjusting portion 100a (right side in the arrow Y direction in FIG. 6) acts on the clutch drum portion 105a via the snap ring S3a. A force acting on the clutch retainer 108a from the left side in the rotational axis P direction (left side in the arrow Y direction in FIG. 6) of the driving force adjusting unit 100a acts via the snap ring S1a. Therefore, the clutch drum portion 105a can receive two forces acting on the hub portion 102a and the clutch retainer 108a. As will be described later, in the present embodiment, the two forces acting on the hub portion 102a and the clutch retainer 108a mean the pressing force generated by the cam mechanism 131 (see FIG. 3) and the reaction force thereof. Yes.

  The drive plate 106a is a substantially disc-shaped plate, and, like the hub portion 102a, a plurality of substantially trapezoidal drive plate protrusions 110a formed on the outer edge of the drive plate 106a and the inner surface of the clutch drum portion 105a. Spline joints are formed by a plurality of drum groove portions 109a each having a substantially trapezoidal shape, and are fitted into the clutch drum portion 105a.

  The driven plate 107a is a substantially disk-shaped plate, and a spline joint is formed by a driven plate protrusion 111a formed on the inner surface of the driven plate 107a and a plate spline shaft portion 112a formed on a part of the shaft 113a. Formed and externally fitted to the shaft 113a.

  The drive plate 106a and the driven plate 107a receive the pressing force from the main cam 132a of the cam mechanism 131a described later, and move the clutch retainer 108a while closing a minute gap between the drive plate 106a and the driven plate 107a. Until it is regulated, the driving force adjusting unit 100a is configured to be operable on the right side in the rotational axis P direction (right side in the Y direction in FIG. 6).

  Accordingly, when the drive plate 106a and the driven plate 107a receive a pressing force from the main cam 132a of the cam mechanism 131a described later and the gap between the drive plate 106a and the driven plate 107a is reduced, the drive plate 106a and the driven plate 107a A frictional force is generated between them. The frictional force generated between the drive plate 106a and the driven plate 107a is increased according to the pressing force from the main cam 132a of the cam mechanism 131a, and the driving force according to the pressing force is transferred from the drive plate 106a to the driven plate 107a. Is transmitted to. As a result, the ratio of the driving force transmitted from the clutch drum portion 105a to the shaft 113a is adjusted.

  An oil seal 121a is disposed between the center holding portion 69a (see FIG. 5) of the center cover 65 and the hub portion 102a. On the other hand, between the hub portion 102a and the shaft 113a, a rubber-like X ring 120a is fitted in a concave groove 102a3 formed in the hub portion 102a. In addition, although illustration is abbreviate | omitted, the oil seal 121b is similarly arrange | positioned between the retainer holding | maintenance part 69b of the retainer cover 65, and the hub part 102a.

  Here, as described above, since the hub portion 102a is rotationally driven while the driving force from the prime mover 10 is transmitted, a large amount of differential is generated with respect to the fixed center cover 65. Only when a slip on the tire 70a side occurs with respect to the rotation of the wheel 70a, a slight difference is generated between the shaft 113a connected to the tire 70a (output) and the hub portion 102a. That is, during normal traveling, there is always a difference between the hub portion 102a and the center cover 65, and when torque distribution is controlled between the hub portion 102a and the shaft 113a. Only a little differential will occur. Therefore, in the present embodiment, the oil seal 121a is disposed in a portion where the differential between the hub portion 102a and the center cover 65 is large, and the X ring 120a is disposed in a portion where the differential between the hub portion 102a and the shaft 113a is small. It is the composition to arrange.

  Further, the oil seal 121a and the X ring 120a can shield the space (side space) covered by the side cover 66a and the space (center space) covered by the center cover 65. Therefore, the lubricating oil covered by the side cover 66a and lubricating the driving force adjusting unit 100a and the lubricating oil covered by the center cover 65 and lubricating the pinion gears 53 and 54 can be of different types, and the driving force adjustment Lubricating oil suitable for the part 100a and the pinion gears 53 and 54 can be used.

  The X ring 120a is disposed between the hub portion 102a and the shaft 113a. However, since no differential occurs between the hub 102a and the shaft 113a, the X ring 120a is disposed between the hub 102a and the shaft 113a. An O-ring may be disposed in place of the ring, and its shape and material are not limited as long as the space covered by the side cover 66a and the space covered by the center cover 65 can be shielded. In addition, the X ring 120a is disposed between the hub portion 102a and the shaft 113a. However, an X or O ring may be disposed between the hub portion 102a and the outer peripheral surface of the output gear unit 52. . With this configuration, since there is no differential between the hub portion 102a and the output gear unit 52, damage to the X or O ring can be suppressed.

  Next, the cam mechanism 131a (see FIG. 3) of the driving force adjusting mechanism 100a will be described in detail. The cam mechanism 131a is an amplifying mechanism that uses the driving force transmitted from the clutch drum portion 105a, and is located at a position facing the clutch retainer 108a in the direction of the rotation axis P of the driving force adjusting portion 100 (the arrow Y direction in FIG. 6). Has been placed.

  The cam mechanism 131a includes a pressing member 140a pressed by a piston mechanism 151a, which will be described later, a plurality of (two in this embodiment) primary drive plates 135a pressed by the pressing member 140a, and a primary drive plate 135a. It is sandwiched between a primary driven plate 136a disposed between the drive plates 135a, a primary cam 133a connected to the primary driven plate 136a, a main cam 132a connected to the shaft 113a, and the primary cam 133a and the main cam 132a. And a plurality of (six in this embodiment) balls 134a and a bearing b2a adjacent to the primary cam 133a.

  The primary drive plate 135a is a substantially disk-shaped plate, and, like the hub portion 102a, a plurality of substantially trapezoidal primary drive plate protrusions 137a formed on the outer edge of the primary drive plate 135a, and a clutch drum portion 105a. A spline joint is formed by a plurality of substantially trapezoidal drum groove portions 109a formed on the inner surface of the inner surface of the inner surface of the inner surface of the clutch drum portion 105a.

  As described above, the drive plate protrusion 110a and the clutch retainer protrusion 115a are formed in the same shape as the hub protrusion 104a of the bubb 102a, and the primary drive plate protrusion 137a is also the hub protrusion 104a. And the same shape. Therefore, the drum groove 109a in which the drive plate protrusion 110a, the clutch retainer protrusion 115a, and the primary drive plate protrusion 137a are fitted has the same shape as the drum groove 109a in which the hub protrusion 104a is fitted. Therefore, since the drum groove 109a formed in the clutch drum portion 105a can be manufactured in the same shape and the specifications can be unified, the manufacture of the clutch drum portion 105a is not complicated, and the manufacturing efficiency can be further improved.

  The primary driven plate 136a is a substantially disk-shaped plate, and a spline joint is formed by a primary driven plate projection 138a and a primary cam projection 139a formed on the inner surface of the primary driven plate 136a, and the primary cam 133a. Is externally fitted.

  Therefore, the primary drive plate 135a and the primary driven plate 136a receive a pressing force from a piston mechanism 151a, which will be described later, to close the minute gap between the primary drive plate 135a and the primary driven plate 136a and rotate the driving force adjusting unit 100a. It is configured to be operable on the right side (right side in the direction of arrow Y in FIG. 6) of the axis P. Further, the primary drive plate 135a has a snap ring S2a fitted into the clutch drum portion 105a, and the right side in the axial direction of the rotational axis P of the driving force adjusting portion 100a with respect to the clutch drum portion 105a (the arrow Y direction in FIG. 6). Movement to the right) is restricted.

  In this way, when the primary drive plate 135a and the primary driven plate 136a receive a pressing force from a piston mechanism 151a, which will be described later, and the gap between the primary drive plate 135a and the primary driven plate 136a is clogged, the primary drive plate 135a and the primary drive plate 135a are closed. A frictional force is generated between the driven plate 136a and the driven plate 136a.

  The frictional force generated between the primary drive plate 135a and the primary driven plate 136a is increased according to the pressing force from the piston mechanism 151a, and the driving force according to the pressing force is changed from the primary drive plate 135a to the primary driven plate. 136a. As a result, the ratio of the driving force transmitted to the primary cam 133a is adjusted.

  A primary cam groove portion 141a is formed on the surface of the primary cam 133a facing the main cam 132a, and a main cam groove portion 142a is formed on the surface of the main cam 132a facing the primary cam 133a. A ball 134a is sandwiched between the primary cam groove 141a and the main cam groove 142a.

  Here, with reference to FIG. 7, the detailed configuration and operation of the primary cam 133a, the main cam 132a, and the ball 134a will be described. FIG. 7A shows a state where the right side (the right side in the arrow Y direction in FIG. 6) is viewed from the left side (the left side in the arrow Y direction in FIG. 6) in FIG.

  As shown in FIG. 7A, the primary cam 133a is a substantially annular member, and is annular on the surface facing the main cam 132a (the surface on the side perpendicular to the paper surface of the primary cam 133a shown in FIG. 7A). Primary cam groove 141a is formed. Further, a primary cam projection 139a is formed on the outer peripheral surface of the primary cam 133a, and the spline joint is formed by the primary cam projection 139a and the primary driven plate projection 138a of the primary driven plate 136a (see FIG. 6). It is formed.

  The main cam 132a is a substantially annular member, and an annular main cam groove 142a is formed on a surface facing the primary cam 133a (a surface on the front side of the main cam 132a shown in FIG. 7A). Yes. A main cam projection 144a is formed on the inner peripheral surface of the main cam 132a. A spline joint is formed by the main cam projection 144a and a cam spline shaft portion 143a (see FIG. 6) formed on the shaft 113a (see FIG. 6). Is formed.

  Further, as shown in FIG. 7A, the primary cam groove portion 141a and the main cam groove portion 142a are formed in the same shape, and a plurality of balls 134a are formed between the primary cam groove portion 141a and the main cam groove portion 142a ( In the present embodiment, six) are accommodated.

  Next, with reference to FIG. 7B, operations of the main cam 132a, the primary cam 133a, and the ball 134a when the driving force is transmitted to the primary cam 133a will be described. As shown in FIG. 7B, the depth of the groove portions of the main cam groove portion 142a and the primary cam groove portion 141a gently change in the circumferential direction (direction of arrow R in FIG. 7B).

  In FIG. 7B, the state indicated by the solid line of the primary cam 133a is the position when the driving force from the clutch drum portion 105a is not transmitted to the primary cam 133a, and the ball 134a The cam groove 141a and the main cam groove 142a are accommodated in a deep portion.

  Note that this position is referred to as a reference position for the description of the release mechanism 171a described later. Further, the distance from the main cam 132a when the primary cam 133a is at the reference position is the width L1 in the direction of the rotation axis P of the driving force adjusting unit 100a (the arrow Y direction in FIG. 7B).

  In FIG. 7B, the state indicated by the broken line of the primary cam 133a is the position when the driving force from the clutch drum portion 105a is transmitted to the primary cam 133a, and the primary cam 133a is in relation to the main cam 132a. And moved in the circumferential direction (right side in the direction of arrow R in FIG. 7B). In this state, the ball 134a is accommodated in a shallower portion than when the driving force is not transmitted to the primary cam 133a (the state indicated by the solid line, the reference position).

  Note that this position is referred to as an operating position for the description of the release mechanism 171a described later. Further, the distance from the main cam 132a when the primary cam 133a is in the operating position is the width L2 in the direction of the rotation axis P of the driving force adjusting unit 100a (the arrow Y direction in FIG. 7B).

  As shown in FIG. 7B, the width of the primary cam 133a and the main cam 132a is wider in the width L2 than in the width L1. This is because when the primary cam 133a is rotated about the rotation axis P of the driving force adjusting unit 100a with respect to the main cam 132a by the driving force transmitted to the primary cam 133a, the ball 134a is formed in each of the grooves 141a and 142a. This is because it rolls to a portion where the depth is shallow, and the width between the primary cam 133a and the main cam 132a increases. As a result, a pressing force and a reaction force against the pressing force are generated between the primary cam 133a and the main cam 132a. The pressing force is amplified to several tens of times (approximately 20 times in the present embodiment) the pressing force generated by the piston mechanism 151a.

  As described above, the cam mechanism 131a (see FIG. 3) can amplify the pressing force generated by the piston mechanism 151a (see FIG. 3) with a simple configuration. Therefore, the piston mechanism 151a (see FIG. 3) generates a large pressing force that presses the drive plate 106a and the driven plate 107a only by generating a small pressing force.

  Further, since the pressing force of the piston mechanism 151a (see FIG. 3) is amplified by the cam mechanism 131a (see FIG. 3), it may be approximately 1/20 of the force pressing the drive plate 106a and the driven plate 107a. . That is, the pressure value to be generated by the oil pump 202a can be set smaller than when the cam mechanism 131a is omitted and the drive mechanism 106a and the driven plate 107a are pressed directly by the piston mechanism 151a.

  Therefore, the electric motor 201a for driving the oil pump 202a can be reduced in size, and the driving force adjusting mechanism 60a (see FIG. 1) can be reduced in weight. Furthermore, since the power consumption of the electric motor 201a can be suppressed, the on-vehicle power generation device (not shown) can be reduced in size, and the four-wheel drive vehicle 1 can be reduced in weight. In addition, since the electric power consumption of the electric motor 201a is reduced, the electric motor 201a can be used as a motor that consumes more power than the electric power consumption, thereby increasing the number of options for the motor. As a result, it is possible to select a motor with a large circulation volume and a low price, and cost can be reduced.

  Further, the cam mechanism 131a (see FIG. 3) presses the connection mechanism 101a (see FIG. 3) by the difference in rotational speed between the clutch drum portion 105a (see FIG. 6) and the shaft 113a (see FIG. 6) (arrow in FIG. 3). (Y direction). That is, the larger the rotational speed difference between the clutch drum portion 105a (see FIG. 6) and the shaft 113a (see FIG. 6), the faster the cam mechanism 131a (see FIG. 3) spreads toward the connection mechanism 101a (see FIG. 3). Will be faster.

  Therefore, if the rotational speed difference between the clutch drum portion 105a (see FIG. 6) and the shaft 113a (see FIG. 6) is set large, the driving force adjustment can be performed even if the gap between the drive plate 106a and the driven plate 107a is set wide. The responsiveness of the mechanism 60a (see FIG. 1) is not impaired. Accordingly, the responsiveness of the driving force adjusting mechanism 60a (see FIG. 1) can be ensured while setting the gap between the drive plate 106a and the driven plate 107a wide to reduce drag.

  Further, since the gap between the drive plate 106a (see FIG. 6) and the driven plate 107a (see FIG. 6) is closed via the cam mechanism 131a (see FIG. 3), the piston mechanism 151a (see FIG. 3) is the primary Only the gap between the drive plate 135a and the primary driven plate 136a may be reduced. Therefore, even if the amount of oil sent from the oil supply mechanism 200a (see FIG. 8) to the piston mechanism 151a (see FIG. 3) is small, the driving force from the clutch drum 105a (see FIG. 6) is used as the shaft 113a (see FIG. 6). ). Therefore, since the oil pump 202a (see FIG. 8) provided in the oil supply mechanism 200a can be reduced in size, the driving force adjusting mechanism 60a (see FIG. 1) can be reduced in weight.

  Here, with reference to FIG. 6, a method of transmitting the pressing force generated by the cam mechanism 131a and its reaction force will be described. In the present embodiment, the pressing force generated by the primary cam 133a, the main cam 132a, and the ball 134a is transmitted via the plurality of drive plates 106a, the plurality of driven plates 107a, the clutch retainer 108a, and the snap ring S1a. Is transmitted to the clutch drum portion 105a. Further, the reaction force of the pressing force generated by the primary cam 133a, the main cam 132a, and the ball 134a is transmitted to the clutch drum portion 105a through the bearing b2a, the hub portion 102a, and the snap ring S3a. That is, the pressing force generated by the cam mechanism 131a and the reaction force thereof are transmitted by the constituent members of the connection mechanism 101a and act on the clutch drum portion 105a.

  Therefore, the pressing force generated by the cam mechanism 131a and the reaction force are transmitted to the clutch drum portion 105a and not to the case 61, the piston mechanism 151a, or the like. Therefore, when ensuring the strength of the driving force adjusting mechanism 60a (see FIG. 1) based on the pressing force generated by the cam mechanism 131a and its reaction force, ensuring the strength of the connection mechanism 101a and the cam mechanism 131a. It is not necessary to secure the strength against the thrust force (force in the direction of arrow Y in FIG. 6) for the case 61, the piston mechanism 151a, the bearing B3a, or the like. As a result, since the number of members whose strength is to be secured is reduced, the piston mechanism 151a or the bearing B3a can be reduced in size and the case 61 can be reduced in thickness. Can be achieved.

  Here, the drag will be described. Dragging is a phenomenon that occurs when the main cam 132a does not generate a pressing force and the main cam 132a has not fully returned from the operating position to the reference position. Specifically, this is a phenomenon in which the driven plate 107a sticks to the drive plate 106a by the oil interposed between the drive plate 106a and the driven plate 107a, and the driven plate 107a is dragged and rotated by the drive plate 106a. . The drag is also generated when the movement of the drive plate 106a and the driven plate 107a varies in the axial direction due to the rotation of the drive plate 106a and the driven plate 107a.

  The release mechanism 171a is a disc spring, and moves the main cam 132a away from the drive plate 106a, the driven plate 107a, and the clutch retainer 108a so that the main cam 132a moves toward the reference position (left side in the Y direction in FIG. 6). In other words, drag between the plurality of drive plates 106a and the plurality of driven plates 107a is reduced. Further, the release mechanism 171a is a substantially annular elastic member, and is nipped and fixed between the main cam 132a and the plate spline shaft portion 112a as shown in FIG. Therefore, when the main cam 132a moves to the drive plate 106a, the driven plate 107a, and the clutch retainer 108a side (right side in the arrow Y direction in FIG. 6), the main cam 132a moves away from the drive plate 106a, the driven plate 107a, and the clutch retainer 108a (arrow Y in FIG. A biasing force is generated in the direction left).

  The release mechanism 171a includes an oil adhesive force acting on the main cam 132a and the drive plate 106a, a main cam protrusion 144a formed on the inner peripheral surface of the main cam 132a, and a cam spline shaft portion 143a formed on the shaft 113a. An urging force that exceeds the combined force of the frictional force, the rolling resistance force of the ball 134a, and the reaction force of the main cam 132a generated by the drag of the primary drive plate 135a and the primary driven plate is generated.

  That is, the release mechanism 171a is set with a spring constant and an initial load that generate an urging force larger than the plurality of forces. As a result, when the pressing force is not supplied from the cam mechanism 131, the main cam 132a moves from the operating position toward the reference position by the urging force of the release mechanism 171a, and drag between the drive plate 106a and the main cam 132a is reduced. Can do. Accordingly, it is possible to reduce transmission of an extra driving force from the clutch drum portion 105a to the shaft 113a by dragging.

  As described above, in the present embodiment, the primary drive plate 135a and the primary driven plate 136a generate a frictional force by a pressing force generated by a piston mechanism 151a (see FIG. 3) described later. The driving force transmitted from the clutch drum portion 105a by the frictional force generated between the primary drive plate 135a and the primary driven plate 136a is amplified by the cam mechanism 131a (see FIG. 3), and the drive plate 106a and the driven plate 107a The frictional force is generated between the two. That is, the friction force can be generated between the plates 135a, 136a, 106a, and 107a by the pressing force of the piston mechanism 151a.

  In addition, the piston mechanism 151a (see FIG. 3) moves the piston body 153a in the direction of the primary drive plate 135a and the primary driven plate 136a (the arrow Y direction in FIG. 6) and pushes it by increasing the pressure generated in the piston chamber 154a. Since the pressure is generated, a gap can be set between the primary drive plate 135a and the primary driven plate 136a to reduce drag.

  On the other hand, there is a method in which a pressing force is generated by an electromagnetic force and a frictional force is generated between the plates 135a, 136a, 106a, and 107a. In this method, a coil is energized to generate an electromagnetic force. A magnetic force is generated inside a member called an armature, and the coil is attracted to the armature, whereby a pressing force can be generated. That is, a plurality of plates (in the present embodiment, the primary drive plate 135a and the primary driven plate 136a are shown) are arranged between the armature and the coil, and the force with which the coil attracts the armature is pressed by the plurality of plates. The friction force is generated between the plates by the pressing force.

  This method of generating a pressing force by electromagnetic force does not use the hydraulic pressure of oil, so it is not easily affected by the viscosity of the oil. Instead, it is necessary to pass a magnetic flux between the armature and the coil. is there. Therefore, in the method of generating a pressing force using electromagnetic force, a plurality of plates must be configured using only members (mainly iron) that allow magnetic flux to pass.

  In order to strongly stabilize the magnetic flux, the plurality of plates described above (in the present embodiment, the primary drive plate 135a and the primary driven plate 136a) and the armature need to be in constant contact with each other. As a result, the plate is dragged, and the cam mechanism 132a generates a thrust force (force in the direction of arrow Y in FIG. 6). As a result, the gap between the drive plate 106a and the driven plate 107a is clogged, and dragging occurs. Therefore, it is necessary to set a spring constant or initial load that exceeds the thrust force of the thrust force in the release mechanism 171a so as not to close the gap between the drive plate 106a and the driven plate 107a. Turn into.

  However, in the present embodiment, the frictional force is generated by the pressing force of the piston mechanism 151a. Therefore, the plate does not have to be configured with a member that allows magnetic flux to pass. Therefore, a material having no magnetic permeability (material other than metal) can be used. Therefore, in the present embodiment, the primary drive plate 135a and the primary driven plate 136a, and the drive plate 106a and the driven plate 107a are configured using a paper material having no magnetic permeability.

  Since this paper material is a material having better judder resistance than a member using a metal material, the case where a plate using a metal material is used for the friction surface of each plate 135a, 136a and 106a, 107a is used. It is necessary to optimize the surface shape of the plate for the purpose of improving judder resistance, special processing such as stabilization of friction characteristics by surface treatment of the plate, use of special oil to improve the friction characteristics, etc. Disappears. As a result, it is not necessary to add a manufacturing process by performing special processing such as optimizing the surface shape of the plate, stabilizing the friction characteristics by surface treatment of the plate, or adding an additive to the oil. The cost can be reduced and the running cost can be reduced.

  Further, since no pressing force is generated by the magnetic flux, it is not necessary to strongly stabilize the magnetic flux, and there is a gap between a plurality of plates (in this embodiment, the primary drive plate 135a and the primary driven plate 136a). Can be made. Therefore, the drag between the primary drive plate 135a and the primary driven plate 136a does not cause the cam mechanism 132a to generate a thrust force and the gap between the drive plate 106a and the driven plate 107a is not clogged. It is not necessary to set a spring constant or an initial load, and the release mechanism 171a can be prevented from becoming large.

  Also, since the pressing force generated using electromagnetic force is not mixed with the pressing force generated by the hydraulic pressure of oil and the pressing force amplified by the driving force, the plate material is unified and one chamber of the oil chamber is used. And the same kind of oil can be used, and cost reduction, parts management man-hours and assembly man-hours can be reduced.

  As described above, in the present embodiment, since the pressing force generated by the hydraulic pressure of oil and the pressing force amplified by the driving force are used, when the pressing force generated using electromagnetic force is used. Compared to this, the selection range of the plate material is widened, the paper material with good judder resistance is selected, the special processing for optimizing the surface shape of the plate and the use of special oil to improve the friction characteristics There is no need. Furthermore, since it is difficult for drag to occur, the control accuracy of the driving force when transmitting a small driving force can be improved.

  Next, the piston mechanism 151a (see FIG. 3) will be described. As shown in FIG. 6, the piston mechanism 151a generates a pressing force by the hydraulic pressure of oil sent from the oil supply mechanism 200a (see FIG. 2), and the pressing force is generated by the cam mechanism 131a (see FIG. 3). A piston chamber 154a filled with oil sent from the oil supply mechanism 200a, a piston main body 153a that generates a pressing force by the hydraulic pressure of the oil sent from the oil supply mechanism 200a, A cylinder portion 152a fitted over the piston main body portion 153a, a stem bleeder 155a (see FIG. 8) that discharges gas (air) mixed in oil filled in the piston chamber 154a, and a drive with respect to the piston main body portion 153a The piston main body is attached to the pressing member 140a of the cam mechanism 131a rotating about the rotation axis P of the force adjusting unit 100a. And a bearing B3a that smoothly transmits the pressing force from the portion 153a.

  The piston chamber 154a is a space formed by fitting a substantially ring-shaped piston body portion 153a into a substantially ring-shaped cylinder portion 152a, and is sent from the oil supply mechanism 200a (see FIG. 2). Filled with coming oil. A stem bleeder 155a, which is a through hole formed in the upper portion of the piston main body 153a, is disposed on the upper portion of the piston chamber 154a (the upper portion in the arrow Z direction in FIG. 8). The piston chamber 154a is an oil recovery chamber 64a. And a stem bleeder 155a. Therefore, the oil sent from the oil supply mechanism 200a to the piston chamber 154a is discharged into the oil recovery chamber 64a together with the gas (air) mixed in the oil.

  The stem bleeder 155a mainly discharges the gas (air) mixed in the oil to the oil recovery chamber 64a. The stem bleeder 155a has an annular gap shape so that the gas (air) mixed in the oil can easily pass through and does not easily pass through the oil. It has been as A detailed description of the stem bleeder 155a will be described later with reference to FIGS.

  The bearing B3a is disposed adjacent to the piston main body 153a (see FIG. 3) and the pressing member 140a of the cam mechanism 131a (see FIG. 3). The pressing member 140a of the cam mechanism 131a is a hub. Since it rotates with rotation of the part 102a, it rotates with respect to the piston main-body part 153a. That is, the bearing B3a operates so as not to generate a resistance due to a difference in rotation, and the pressing force transmitted from the piston main body 153a is smoothly transmitted to the pressing member 140a of the cam mechanism 131a.

  Further, since the pressing force transmitted from the piston main body 153a (see FIG. 3) is amplified by the cam mechanism 131a (see FIG. 3), the piston main body 153a is compared with the case where the cam mechanism 131a is not provided. The pressing force transmitted from can be made sufficiently small. Therefore, compared with the case where the cam mechanism 131a is not provided, the bearing B3a can have a low load, and the number of options for the bearing B3a can be increased and the cost can be reduced.

  As shown in FIG. 6, a pair of regulating walls 161 a protruding from a part of the inner wall is formed on the inner wall of the center cover 65 on the driving force adjusting unit 100 a side. The restriction wall 161a is provided to restrict the rotation of the piston main body 153a in the rotation direction R. A detailed description of the restriction wall 161a will be described later with reference to FIG.

  Next, a detailed configuration of the oil supply mechanism 200a will be described with reference to FIG. FIG. 8 is a cross-sectional view showing the driving force adjusting mechanism 60a along the line VIII-VIII in FIG. In FIG. 8, reference numerals related to the connection mechanism 101a, the cam mechanism 131a, and the release mechanism 171a are omitted. Further, the arrow Y shown in FIG. 8 indicates the left-right direction of the four-wheel drive vehicle 1 and indicates the direction of the rotational axis P of the drive force adjusting unit 100a, and the arrow Z indicates the vertical direction of the four-wheel drive vehicle 1. ing.

  As shown in FIG. 8, the oil supply mechanism 200a feeds oil to the driving force adjusting unit 100a. The oil supply mechanism 200a is fed by the electric motor 201a, the oil pump 202a driven by the electric motor 201a, and the oil pump 202a. The oil storage chamber 204a in which the oil to be stored is stored, and the electric motor convex portion 203a that forms a wall portion of the oil storage chamber 204a between the electric motor 201a and the oil pump 202a.

  As shown in FIG. 8, the electric motor 201a, the electric motor convex portion 203a, and the oil pump 202a are disposed adjacent to the rotation axis P direction (arrow Y direction in FIG. 8) of the driving force adjusting portion 100a. Yes. The oil storage chamber 204a includes an electric motor 201a that is in close contact with one end surface of the electric motor convex portion 203a (the surface on the right side in the arrow Y direction in FIG. 8) and the other end surface of the electric motor convex portion 203a (the arrow Y in FIG. 8). It is a space formed by being surrounded by the oil pump 202a and the electric motor convex portion 203a that are in close contact with the left surface in the direction). That is, the electric motor 201a and the oil pump 202a also serve as the wall portion of the oil storage chamber 204a.

  The electric motor 201a has a motor shaft portion 207a that is a cylindrical shaft that outputs a rotational force. The motor shaft portion 207a passes through the oil storage chamber 204a and is connected to the oil pump 202a. That is, the motor shaft portion 207a is disposed in a part of the space of the oil storage chamber 204a, and the electric motor 201a and the oil pump 202a are connected with the shortest distance (on a straight line). Therefore, the place where the motor shaft portion 207a is disposed outside the oil storage chamber 204a can be omitted, and the apparatus composed of the electric motor 201a, the electric motor convex portion 203a, and the oil pump 202a can be reduced in size.

  Further, since the oil reservoir chamber 204a is disposed adjacent to the oil pump 202a in a horizontal position, for example, the oil reservoir chamber is disposed below the oil pump 202a and the oil reservoir disposed below the oil reservoir chamber 204a. The work of sucking up oil and the pipe resistance in the passage can be reduced as compared to the case of sucking up oil from the chamber through the suction passage.

  The oil pump 202a has a pump suction port 205a on the right side (the surface on the right side in the arrow Y direction in FIG. 8) and a pump discharge port 206a on the left side (the surface on the left side in the arrow Y direction in FIG. 8). That is, the oil supply mechanism 200a is able to efficiently send out the oil without being affected by the pipe resistance because the oil is sent in a linear direction when the oil is sent out from the oil storage chamber 204a.

  The electric motor convex portion 203a is a substantially cylindrical member having the same diameter as the oil pump 202a, and has an oil recovery hole 208a and a pump inner wall 209a. The oil recovery hole 208a is a through hole installed in the upper part (upper side in the arrow Z direction in FIG. 8) of the electric motor convex part 203a, and is connected to the oil recovery chamber 64a via the recovery passage 210a. The pump inner wall 209a is an inner wall of the electric motor convex portion 203a that is coupled to the oil recovery hole 208a, and is formed to be inclined upward toward the oil recovery hole 208a.

  Accordingly, when oil mixed with gas (air) flows from the oil recovery chamber 64a into the oil storage chamber 204a, the oil (air) is transferred to the oil recovery hole 208a without being retained in the oil storage chamber 204a, and the recovery path Only gas (air) can be returned to the oil recovery chamber 64a via 210a.

  Furthermore, the pump suction port 205a is installed in the deep part (lower part in the arrow Z direction in FIG. 8) of the oil storage chamber 204a. Therefore, since the ratio of the gas (air) reaching the deep part of the oil storage chamber 204a is very small, the gas (air) remains in the pump intake port 205a even while the gas (air) stays in the oil storage chamber 204a. From the oil to the oil pump 202a can be greatly reduced.

  As described above, the mixed gas (air) is easily discharged into the oil recovery chamber 64a and is difficult to flow into the oil pump 202a. Therefore, a difference that occurs when oil and gas (air) are mixed into the oil pump 202a. The sound can be suppressed and gas (air) is not easily mixed into the oil sent out by the oil pump 202a, the damper effect is reduced, and the hydraulic pressure of the oil generated by the oil pump 202a is reduced to a desired hydraulic pressure (piston) The hydraulic pressure required for pressing the mechanism 151a can be increased.

  The oil pump 202a and the electric motor convex portion 203a are substantially cylindrical members having the same diameter, and are integrally fitted into a concave portion insertion hole 213a formed on the outer edge of the case 61, and the electric motor 201a is attached to the case. By fixing to 61, the oil pump 202a is pressed against and fixed to the case 61 by the electric motor convex portion 203a.

  Thus, the electric motor 201a, the electric motor convex portion 203a, and the oil pump 202a are disposed adjacent to each other in the horizontal direction (the arrow Y direction in FIG. 8), and the electric motor 201a and the electric motor convex portion are arranged. Since the diameter of 203a is the same, the electric motor 201a and the electric motor convex portion 203a can be inserted into the concave portion insertion hole 213a and can be easily assembled.

  Further, since the electric motor 201a, the electric motor convex portion 203a, and the oil pump 202a are integrally formed adjacent to each other in the direction of the rotation axis P, not only the oil supply mechanism 200a can be downsized but also the electric motor. 201a, electric motor convex part 203a, and oil pump 202a can be combined and used for another apparatus easily. Therefore, the versatility of the apparatus in which the electric motor 201a, the electric motor convex portion 203a, and the oil pump 202a are integrally formed can be improved.

  The oil supply mechanism 200a collects the circulated oil mixed with gas (air), separates the gas (air), and then sends the oil to the piston mechanism 151a. However, it is very difficult to completely remove the gas (air) mixed in the oil. Therefore, in the piston mechanism 151a, a stem bleeder 155a is disposed at the upper part of the piston chamber 154a (the upper part in the arrow Z direction in FIG. 8) in order to remove the gas (air) mixed in the oil.

  Therefore, even when oil mixed with gas (air) is sent to the piston mechanism 151a, the gas (air) is naturally transferred to the upper portion of the piston chamber 154a, and the gas (air) accumulated in the piston chamber 154a is The oil is discharged from the stem bleeder 155a together with the oil to the oil recovery chamber 64a.

  In this way, even if oil mixed with gas (air) is sent to the piston chamber 154a, the gas (air) is discharged without stagnation, so the hydraulic pressure of the oil sent from the oil supply mechanism 200a Can be stably changed to the pressing force of the piston main body 153a.

  If the oil pump 202a is stopped for a long time, the oil in the piston chamber 154a gradually flows back to the oil recovery chamber 64a through the gap of the oil pump 202a, and the oil change in the piston chamber 154a occurs. Gas (air) flows through the stem bleeder 155a.

  As described above, when the pressure in the piston chamber 154a is increased to a predetermined pressure from the state where gas (air) flows into the piston chamber 154a, the piston chamber 154a needs to be filled with oil. Until the gas is filled, since the gas (air) is mixed, the pressure in the piston chamber 154a rises slowly. Therefore, it takes time to reach a predetermined pressure value, and the control accuracy deteriorates.

  Here, in the present embodiment, the electric motor 201a is always operated and oil is always supplied into the piston chamber 154a. Thereby, the inside of the piston chamber 154a is always filled with oil, and the time for the piston chamber 154a to be filled with oil is omitted. Therefore, there is no delay in the pressure increase in the piston chamber 154a, and the control accuracy can be improved.

  The magnitude of the pressure value in the piston chamber 154a may be larger than the sliding resistance of the piston seal members 218a and 219a. In this case, the piston main body 153a can generate a pressing force to close the gap between the primary plate 135a and the primary driven plate 136a. Therefore, the driving force is transmitted from the primary plate 135a to the primary driven plate 136a without delaying the pressure increase in the piston chamber 154a.

  Therefore, there is no response delay in the driving force transmission with respect to the pressure increase in the piston chamber 154a, and the responsiveness can be increased while improving the control accuracy.

  Furthermore, the magnitude of the pressure value in the piston chamber 154a may be set so that the pressing force generated by the connection mechanism 101a by the pressure value is smaller than the urging force of the release mechanism 171a. In this case, since the pressing force from the cam mechanism 131a does not act on the drive plate 106a and the driven plate 107a, drag can be reduced between the drive plate 106a and the driven plate 107a. Therefore, it is possible to reduce transmission of excess driving force from the clutch drum portion 105a (see FIG. 6) to the shaft 113a (see FIG. 6).

  Further, the biasing force of the release mechanism 171a described above may be set to a lower limit biasing force when mass-produced. In this case, since the pressing force from the cam mechanism 131a does not act on the drive plate 106a and the driven plate 107a even in a mass-produced product, drag can be reduced between the drive plate 106a and the driven plate 107a. Therefore, even in a mass-produced product, it is possible to reduce transmission of excess driving force from the clutch drum portion 105a (see FIG. 6) to the shaft 113a (see FIG. 6).

  As described above, in the present embodiment, the oil pump 202a constantly generates a predetermined pressure in the piston chamber 154a, thereby reducing drag generated between the drive plate 106a and the driven plate 107a, and extra driving. Responsiveness can be improved without transmitting power.

  Next, the air breather mechanism will be described with reference to FIG. FIG. 9 is a view schematically showing the vicinity of the piston main body 153a. FIG. 9A is a front view of the piston main body 153a in a state where the side cover 66a and the driving force adjusting unit 100a are removed from the center cover 65. FIG. 9B is a cross-sectional view of a part of the piston main body 153a and a part of the center cover 65 along the line IXb-IXb in FIG. 9A.

  In FIG. 9, the arrow X is the front-rear direction of the four-wheel drive vehicle 1, and the arrow Y is the left-right direction of the four-wheel drive vehicle 1, and indicates the direction of the rotation axis P of the driving force adjusting units 100 a and 100 b. The arrow Z indicates the vertical direction of the four-wheel drive vehicle 1.

  As shown in FIG. 9A, the inner wall 65a1 of the center cover 65 is provided with a pair of restriction walls 161a protruding from the inner wall 65a1, and an insertion portion 162a is formed between the pair of restriction walls 161a. Has been. Further, the insertion portion 162a of the regulation wall 161a is moved forward (see FIG. 9A) from the vertical line passing through the rotational axis P of the driving force adjusting portion 100a (on the line indicated by the arrow Z in FIG. 9). Arranged at a position deviated by a predetermined angle (30 degrees in the present embodiment) in the direction of arrow X to the right.

  The piston main body 153a is formed with a protrusion 153a1 that protrudes outward (in the direction of the side cover 66a) from the outer periphery thereof, and the protrusion 153a1 is disposed so as to be inserted into the insertion portion 162a of the restriction wall 161a. Has been.

  Therefore, as described above, oil is supplied to the piston chamber 154a by the electric motor 200a, and the piston main body 153a presses the pressing member 140a (see FIG. 6), and dragging accompanying the rotation of the pressing member 140a. Can occur in the piston main body 153a, the rotation of the piston main body 153a with respect to the center cover 65 can be restricted by the protrusion 153a1 coming into contact with the end surface of the restriction wall 161a.

  As shown in FIG. 9A, a breather hole 65a2 is formed in the inner wall 65a1 of the center cover 65, between the pair of regulating walls 161a and in the center of the insertion portion 162a. The breather hole 65a2 is a communication hole that communicates the space (side space) covered with the side cover 66a with the outside.

  As shown in FIG. 9B, the protrusion 153a1 protrudes further from the pressing surface 153a2 on the pressing member 140a side of the piston main body 153a to the pressing member 140a side, and outward from the outer periphery of the piston main body 153a. Is formed to protrude. Since the piston main body 153a transmits the pressing force to the pressing member 140a by the pressing surface 153a2, the distance from the rotation axis P of the piston main body 153a to the maximum diameter is the largest from the rotation axis P of the pressing member 140a. It is longer than the distance to the remote location.

  Further, a breather communication path 65a3 communicating with the breather hole 65a2 is formed on the inner wall of the center cover 65, and a breather chamber 65a4 communicating with the breather communication path 65a3 is disposed outside the center cover 65. That is, the breather hole 65a2 communicates with the outside via the breather communication passage 65a3 and the breather chamber 65a4.

  Therefore, even if the piston main body 153a is dragged in the rotation direction of the pressing member 140a with the rotation of the pressing member 140a and the protrusion 153a1 contacts the end surface of the regulating wall 161a, the breather hole 65a2 And the protruding portion 153a1 are arranged to face each other. Therefore, it is possible to prevent the breather hole 65a2 from being completely exposed in the space covered by the side cover 66a, and the protrusion 153a1 functions as a plate that obstructs the communication of the breather hole 65a2. That is, the protrusion 153a1 functions as a baffle plate that suppresses oil that lubricates the driving force adjusting unit 100a from flowing out of the breather hole 65a2 in the side cover 66a. Therefore, a plate that covers the breather hole 65a2 becomes unnecessary, and a space for attaching the plate becomes unnecessary, so that cost reduction, weight reduction, and downsizing can be achieved.

  Further, the portion of the piston main body 153a that presses the pressing member 140a is the pressing surface 153a2, and the protruding portion 153a1 does not press the pressing member 140a. Therefore, the protruding portion 153a1 has a strength capable of pressing the pressing member 140a. There is no need to have. Therefore, since it is not necessary to form the protrusion 153a1 as thick as the piston main body 153a, it is possible to prevent the lubricating oil from flowing out from the breather hole 65a2 while reducing the size, cost, and weight.

  Furthermore, as described above, the piston main body portion 153a is fitted into the cylinder portion 152a, but the projection portion 153a1 protrudes from the cylinder portion 152a and is disposed to face the inner wall 65a1 of the center cover 65. Therefore, the inner wall 65a1 of the center cover 65 does not need to have a complicated shape corresponding to the protruding portion 153a1, so that the productivity of the center cover 65 can be improved.

  Further, the protruding portion 153a1, the regulating wall 161a (and the insertion portion 162a), and the breather hole 65a2 are moved forward from the vertical line passing through the rotation axis P (on the line indicated by the arrow Z in FIG. 9) (see FIG. 9). Since it is disposed at a position shifted by a predetermined angle (30 degrees in the present embodiment) in 9 (a) arrow X right direction), it is inclined toward the forward side of the four-wheel drive vehicle 1 (rightward in FIG. 9 (a)). Are arranged. Therefore, the lubricating oil or the like in the side cover 66a moves to the backward side of the four-wheel drive vehicle 1 (left side in FIG. 9A), and thus moves away from the breather hole 65a2. Therefore, it is possible to efficiently suppress the lubricating oil or the like from flowing out from the breather hole 65a2. In addition, by arranging the protruding portion 153a1, the regulating wall 161a (and the insertion portion 162a), and the breather hole 65a2 to be inclined, the lubricating oil attached to the protruding portion 153a1 and the like can easily flow downward due to its own weight.

  In the description of FIG. 9, the relationship between the center cover 65 and the piston main body 153a has been described, but the relationship between the retainer cover 67 and the piston main body 153b is configured in the same manner. In this case, the protrusion 153a1 is the protrusion 153b1, the pressing surface 153a2 is the pressing surface 153b2, the restriction wall 161a is the restriction wall 161b, the insertion portion 162a is the insertion portion 162b, the inner wall 65a1 is the inner wall 67b11, and the breather hole 65a2 is the breather. The hole 67b12, the breather communication path 65a3 is replaced with the breather communication path 67b13, and the breather chamber 65a4 is replaced with the breather chamber 67b14.

  Next, the detailed structure of the stem bleeder 155a will be described with reference to FIGS. FIG. 10 is an enlarged cross-sectional view of the vicinity of the stem bleeder 155a indicated by the arrow B in FIG.

  As shown in FIG. 9, in the stem bleeder 155a, a concave groove 155a1 is formed in the pressing surface 153a2 which is an end surface of the piston main body 153a on the bearing B3a (driving force adjusting unit 100a) side. The concave groove 155a1 is formed on a vertical line passing through the rotation axis P (on the line in the direction of arrow Z passing through the rotation axis P in FIG. 9), and at the uppermost part of the groove 155a1, the piston chamber 154a is formed. Openings 155a2 of communication passages 155a3 to 155a5 (see FIG. 10) communicating with each other are formed.

  Therefore, since the groove 155a1 including the opening 155a2 is formed in the pressing surface 153a2 of the piston main body 153a, even if the bearing B3a is in contact with the pressing surface 153a2, the communication path 155a3 is formed by the groove 155a1. The communication between 155a5 and the driving force adjusting unit 100a can be ensured reliably.

  As shown in FIG. 10, a communication passage that communicates between the piston chamber 154a and the bearing B3a (driving force adjustment unit 100a (see FIG. 8)) side is formed in the piston main body 153a. The communication path is formed with an opening 155a2 at the end and a first communication path 155a3 communicating with the space on the bearing B3a side, and a second communication path formed with an inner diameter smaller than the first communication path 155a3 and communicating with the piston chamber 154a. 155a4, and a second communication path 155a4 and a first communication path 155a3 connected to each other to form a substantially dish-shaped third communication path 155a5.

  A cylindrical pin 155a6 having an outer diameter slightly smaller (for example, 0.5 mm smaller) than the inner diameter of the first communication path 155a3 is disposed in the first communication path 155a3. An annular gap is formed between the first communication path 155a3 and the pin 155a6, and the gas (air) mixed with the oil is discharged to the driving force adjusting unit 100a side while suppressing the deterioration of the hydraulic characteristics. Thus, the oil flows into the oil recovery chamber 64a.

  The third communication path 155a5 is formed in a substantially dish shape, and is provided between the first communication path 155a3 and the second communication path 155a4. Therefore, the third communication path 155a5 is disposed on the first communication path 155a3 side of the second communication path 155a4. It is possible to prevent the opening and the pin 155a6 from coming into contact with each other, and it is possible to prevent adverse effects such as no discharge of gas or oil through the stem bleeder 155a.

  Further, the pin 155a6 is restricted from moving toward the piston chamber 154a by a third communication passage 155a5 formed in a substantially dish shape, and is restricted from moving toward the driving force adjusting unit 100a by a bearing B3a. That is, the protrusion of the pin 155a6 toward the driving force adjusting unit 100a can be restricted by the bearing B3a that absorbs the differential between the pressing member 140a and the piston main body 153a. Therefore, it is not necessary to separately attach a plate member or the like for preventing the pin 155a6 from jumping out from the first communication path 155a3 to the driving force adjusting unit 100a side, and a space for attaching the plate member is not necessary. The overall cost of the mechanism 60a can be reduced and the scale can be reduced.

  Moreover, since not only gas but oil is discharged | emitted from opening 155a2, supply of oil to bearing B3a can be performed reliably. Therefore, the oil discharged from the opening 155a2 can act as the lubricating oil for the bearing B3a, and the bearing B3a can be smoothly slid. Furthermore, since it is not necessary to provide a separate passage for supplying oil to the bearing B3a, the cost can be reduced and the space can be reduced accordingly.

  If the relationship between the communication paths 155a3 to 155a5 and the pin 155a6 is adjusted and the amount of oil discharged from the opening 155a2 is adjusted, not only the bearing B3a but also the driving force adjusting unit 100a is used by the oil discharged from the opening 155a2. It can also be used as a lubricating oil. When the lubricating oil of the driving force adjusting unit 100a can be supplied only with the oil discharged from the opening 155a2, the supply path for the lubricating oil is not required, and therefore the cost and scale can be further reduced.

  Here, a case where a stem bleeder mechanism is formed on the center cover 65 will be described. Generally, a cover that covers the driving force distribution mechanism 50 and the driving force adjustment mechanism 60a is manufactured by casting because the outer shape and the inner shape are complicated. Therefore, when the stem bleeder mechanism as in the present embodiment is to be formed on the center cover 65, the inner shape (structure) of the center cover 65 becomes complicated, the mold becomes expensive, and the manufacture of the center cover 65 becomes difficult. End up.

  However, according to the present embodiment, since the communication passages 155a3 to 155a5 of the stem bleeder 155a are produced in the piston main body 153a, it is possible to prevent the inner shape (structure) of the center cover 65 from becoming further complicated. Can do. Therefore, it can suppress that the casting_mold | template for manufacturing the center cover 65 becomes expensive, and can suppress that manufacture of the center cover 65 becomes difficult.

  Further, in the hole machining for forming the communication passages 155a3 to 155a5 of the stem bleeder 155a, generally, the machining position is set based on the distance and angle from the reference point, and must be within a predetermined tolerance range. Therefore, the larger the parts forming the communication paths 155a3 to 155a5, the easier the displacement of the machining position. On the other hand, the smaller the parts, the less the displacement of the machining position. In the present embodiment, since the communication passages 155a3 to 155a5 are formed in the piston main body 153a which is a small part with respect to the center cover 65 and the like, the displacement of the machining position is reduced, and accuracy can be easily ensured.

  Although the present invention has been described based on the embodiments, the present invention is not limited to the above-described embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. Can be easily guessed.

  For example, the numerical values (for example, the quantity, size, angle, etc. of each component) given in the above embodiments are examples, and other numerical values can naturally be adopted.

  In each of the above embodiments, a disc spring is used for the release mechanism 171a. However, it is not always necessary to use a disc spring. For example, a ring-shaped rubber-like elastic body may be used.

  In the above embodiments, the motor covers 68a and 68b are integrally formed with the side covers 66a and 66b. However, the motor covers 68a and 68b are provided separately from the side covers 66a and 66b. Also good. Even in this configuration, the side covers 66a and 66b and the motor covers 68a and 68b can be made into common parts, so that the cost can be reduced.

  In each of the above embodiments, the bubb protrusion 104a, the drive plate protrusion 110a, the primary drive plate protrusion 137a, the clutch retainer protrusion 115a, and the drum groove 109a are formed by substantially trapezoidal protrusions or grooves. However, it may be formed in a substantially rectangular shape, may be formed in a substantially triangular shape, may be formed in a substantially semicircular shape, and may have any shape as long as it can form a spline joint. good.

  In each of the above embodiments, the piston main body portions 153a and 153b are configured to uniformly press the circumferential direction of the driving force adjusting portion 100a. However, a part of the driving force adjusting portion 100a in the circumferential direction is pressed. You may comprise so that it may do. Even in this configuration, the plates 161a and 161b have notches 162a and 162b, and the piston main body portions 153a and 153b have protrusions 153a1 and 153b1, and the protrusions 153a1 and 153b1 form the breather holes 65a2 and 67b12. You may comprise so that it may obstruct.

  Below, the modification of the driving force transmission apparatus of this invention is shown.

  And a pair of output units capable of intermittently outputting the driving force input to the input shaft, and a pair of output units capable of intermittently outputting the driving force input to the input shaft. In the driving force transmission device in which the output unit is arranged on both sides, a first gear coupled to the outer peripheral portion of the input shaft, a second gear meshing with the first gear, and an inner peripheral portion of the second gear A transmission shaft that transmits the driving force input to the input shaft to the input sides of the pair of output units, a center cover that covers the first gear, the second gear, and the transmission shaft, and the center cover A side connecting portion through which a connecting member is inserted, and a pair of side covers that respectively cover the pair of output units, and a position corresponding to the side connecting portion of the side cover. A retainer connecting portion through which a linking member is inserted; and a retainer cover disposed between the center cover and a side cover that covers the one output unit, and covers the retainer cover and the one output unit. The side cover is a driving force transmission device A1 in which the connecting member is inserted through the side connecting portion and the retainer connecting portion and fastened together with the center cover.

  In the driving force transmission device A1, the pair of side covers are configured such that the side connecting portions are formed at substantially equal intervals in the circumferential direction, and the outer shape is formed in substantially the same shape. Device A2.

  In the driving force transmission device A1 or A2, the output unit includes a multi-plate clutch mechanism capable of intermittently outputting the driving force input to the input side via the transmission shaft to the output side, and the multi-plate clutch mechanism. A piston for generating a pressing force for transitioning the driving force input to the input side to a state for outputting to the output side, and supplying a hydraulic pressure for the piston to generate the pressing force; A driving force transmission device A3, comprising: a motor disposed outside; and a motor cover portion that covers the motor is integrally formed on the side cover.

  In the driving force transmission device A3, the motor is disposed at a position where the shaft center of the motor and the shaft center of the side cover are substantially parallel to each other.

  In the driving force transmission device A3 or A4, the motor cover portion is formed in a cylindrical shape having openings formed at both ends in the axial direction of the motor.

  In any one of the driving force transmission devices A1 to A5, the output unit is capable of intermittently outputting the driving force input to the input side via the transmission shaft to the output side, and the transmission shaft. A transmission member coupled to the outer peripheral portion of the transmission shaft and transmitting the driving force of the transmission shaft to the multi-plate clutch mechanism; an output unit space provided on the inner peripheral portion of the transmission member and surrounded by the side cover; and the center A first shielding member made of an elastic material that shields the center space surrounded by the cover, and a reinforcing ring made of a metal material provided at a position on the outer peripheral portion of the transmission member and facing the retainer cover or the center cover. And a second shielding member that shields the output unit space and the center space. Driving force transmitting device A6 according to claim Rukoto.

  In any one of the driving force transmission devices A1 to A5, the output unit has a plurality of input side plates on the input side and a plurality of output side plates on the output side located between the plurality of input side plates. A multi-plate clutch mechanism capable of intermittently outputting the driving force input to the input side via the transmission shaft to the output side by intermittently connecting the output side plate and the input side plate; A substantially conical body that is connected to the outer periphery of the shaft, transmits the driving force of the transmission shaft to the multi-plate clutch mechanism, and has an outer diameter that increases from the connecting portion with the transmission shaft toward the multi-plate clutch mechanism. And a drum portion connected to the maximum diameter portion of the transmission member and connected to the plurality of input side plates. Force transmission device A7.

  In the driving force transmission device A7, a transmission fitting portion in which a concave portion and a convex portion are continuous is formed on the outer peripheral surface of the maximum diameter portion of the transmission member, and the outer peripheral surface of the input side plate of the multi-plate clutch is A plate fitting portion in which the concave portion and the convex portion are continuous is formed, and a first drum fitting in which the convex portion and the concave portion to be fitted to the transmission fitting portion are continuous on the inner peripheral surface of the drum portion. And a second drum fitting portion in which a convex portion and a concave portion that are fitted to the plate fitting portion are formed, and the first drum fitting portion and the second drum fitting portion are: The driving force transmission device A8 is characterized in that a continuous shape of the convex portion and the concave portion is formed in substantially the same shape when the plates of the multi-plate clutch are viewed in the arrangement direction.

  A prime mover that generates a driving force, an input shaft to which the driving force generated by the prime mover is input, a transmission mechanism that transmits the driving force input to the input shaft to the output shaft, and a cover that covers the transmission mechanism A driving force transmission device having a pressure adjustment function for adjusting the pressure in the cover, wherein the transmission mechanism is configured such that the output shaft is coupled to a shaft center portion and the driving force input to the input shaft is output to the output shaft. A clutch mechanism capable of intermittently outputting to the shaft, a piston for generating a pressing force for causing the clutch mechanism to transition to a state in which the driving force input to the input shaft is output to the output shaft, and a piston of the piston A projecting piece formed by projecting outward from the outer edge portion; and an insertion portion that is fixed along the outer edge portion of the piston and into which the projecting piece is inserted. Regulation A restriction member formed on a portion of the inner wall of the cover member corresponding to the insertion portion of the restriction member, and having a communication hole that communicates the inside and the outside of the cover. A driving force transmission device B1.

  In the driving force transmission device B1, the communication hole is positioned substantially at the center of the insertion portion in a first direction corresponding to the rotation direction of the output shaft, and the protruding piece has a length in the first direction. Is formed in half or more of the width of the insertion part in the first direction.

  In the driving force transmission device B1 or B2, the insertion portion, the protruding piece, and the communication hole are located at a position deviating from a vertical line passing through the axis of the output shaft and above the output shaft. A driving force transmission device B3 characterized by the above.

  In any one of the driving force transmission devices B1 to B3, the cover is formed with a piston housing portion that houses at least an end portion of the piston on the side opposite to the clutch mechanism, and the protruding piece is an end on the clutch mechanism side. The driving force transmission device B4 is formed in a portion and located outside the piston housing portion.

  The driving force transmission device B4 includes a pressing member that transmits a pressing force generated by the extension operation of the piston to the clutch mechanism, and the piston is formed in a substantially cylindrical shape, and is formed from the axis of the output shaft. The driving force transmission device B5 is configured such that the distance to the maximum diameter is longer than the distance from the axis of the output shaft to the farthest position of the pressing member.

  A prime mover that generates a driving force, an input shaft to which the driving force generated by the prime mover is input, a transmission mechanism that transmits the driving force input to the input shaft to the output shaft, and a cover that covers the transmission mechanism The transmission mechanism includes a clutch mechanism in which the output shaft is coupled to an axial center portion, and the driving force input to the input shaft can be intermittently output to the output shaft; A piston that generates a pressing force for causing the clutch mechanism to transition to a state in which the driving force input to the input shaft is output to the output shaft, and a piston housing portion that houses the piston and is formed in a part of the cover And a hydraulic pressure supply chamber that is formed between the piston accommodating portion and the piston and is supplied with a hydraulic pressure that generates the pressing force, and is formed in the piston, the hydraulic pressure supply chamber and the clutch mechanism side Driving force transmitting device C1, characterized in that it comprises a communication passage for communicating the space.

  In the driving force transmission device C1, a substantially cylindrical columnar member housed in the communication path and having an outer diameter smaller than the inner diameter of the communication path is disposed between the piston and the clutch mechanism. A pressing force mechanism that transmits the generated pressing force to the clutch mechanism, wherein the communication path has an inner diameter on the hydraulic pressure supply chamber side smaller than an outer diameter of the columnar member, and an opening on the clutch mechanism side has the opening A driving force transmission device C2 that is obstructed by a pressing mechanism.

  In the driving force transmission device C2, the pressing mechanism is arranged between a pressing member that rotates as the input shaft rotates and presses the multi-plate clutch mechanism, and between the pressing member and the piston. A driving force transmission device C3 provided with a differential absorbing member that is provided and absorbs differential rotation between the pressing member and the piston.

  In any one of the driving force transmission devices C1 to C3, the piston has a concave groove formed at a position including the opening of the communication path on the clutch mechanism side. C4.

1 is a schematic view of a four-wheel drive vehicle 1 according to an embodiment of the present invention. It is an external view of a driving force adjustment mechanism. It is sectional drawing of the driving force distribution mechanism and driving force adjustment mechanism in the III-III line of FIG. It is sectional drawing of the driving force distribution mechanism and driving force adjustment mechanism in the IV-IV line of FIG. It is sectional drawing of the case in the IV-IV line of FIG. It is sectional drawing to which the A section of FIG. 3 was expanded. It is the figure which showed the outline of the cam mechanism, (a) is a side view of a cam mechanism. (B) is sectional drawing of the cam mechanism in the VIIb-VIIb line | wire of Fig.7 (a). It is sectional drawing of the driving force adjustment mechanism in the VIII-VIII line of FIG. It is the figure which showed the outline of the piston main-body vicinity, (a) is a front view of the piston main-body part of the state which removed the side cover and the driving force adjustment part from the center cover, (b) is FIG. It is sectional drawing of a part of piston main-body part and a part of center cover in the IXb-IXb line | wire of a). FIG. 9 is an enlarged cross-sectional view showing the vicinity of the stem bleeder indicated by arrow B in FIG. 8 in an enlarged manner.

Explanation of symbols

10 Motor 51 Input gear unit (part of input shaft)
52 Output gear unit (part of transmission shaft)
53 Hypoid gear (first gear)
54 Hypoid gear (second gear)
50 Driving force distribution mechanism (part of input shaft)
60a, 60b Driving force adjustment mechanism (part of output unit)
61 Case (Center cover, side cover, retainer cover)
65 Center cover 65a1 Inner wall (inner wall of cover)
65a2 breather hole (communication hole)
66a, 66b Side cover 66a1, 66b1 Insertion hole (side connecting part)
67 Retainer cover 67b1 insertion hole (retainer connecting part)
67b11 inner wall (inner wall of the cover)
67b12 Breather hole (communication hole)
68a, 68b Motor cover (motor cover part)
94 Central drive shaft (part of input shaft)
100a, 100b Driving force adjuster (multi-plate clutch mechanism, clutch mechanism)
102a, 102b Hub portion (transmission member)
102a1, 102b1 cylindrical part (a part of transmission member)
102a2, 102b2 Dish-shaped part (part of transmission member)
104a, 104b Hub protrusion (transmission fitting part)
105a, 105b Clutch drum part (drum part)
106a, 106b Drive plate (part of input side plate)
107a, 107b Driven plate (part of output side plate)
109a, 109b Drum groove portion (first drum fitting portion, second drum fitting portion)
110a, 110b Drive plate protrusion (part of plate fitting portion)
113a, 113b Shaft (Output shaft)
140a, 140b Pressure member 151a, 151b Piston mechanism 151a1, 151b1 Projection (projection piece)
152a, 152b Cylinder part (piston accommodating part)
153a, 153b Piston body (piston)
154a, 154b Piston chamber (hydraulic supply chamber)
155a, 155b Stem bleeder (communication path)
155a1, 155b1 opening (Clutch mechanism side opening)
155a2, 155b2 groove (groove)
155a3, 155b3 first communication path (part of communication path)
155a4, 155b4 Second communication path (part of communication path)
155a5, 155b5 Third communication path (part of communication path)
155a6, 155b6 pin (cylindrical member)
161a, 161b Restriction wall (regulation member)
162a, 162b Intercalation parts 201a, 201b Electric motor (motor)
B bolt (connecting member)
B3a, B3b Bearing (differential absorbing member)
P Rotation axis of the driving force adjustment part (axis of the side cover, axis of the second gear)
Q Electric motor shaft center (motor shaft center)
R Circumferential direction around the rotation axis P (circumferential direction of the side cover)
T Rotational axis of the driving force distribution mechanism (axis of the first gear)

Claims (5)

A prime mover that generates a driving force, an input shaft to which the driving force generated by the prime mover is input, a transmission mechanism that transmits the driving force input to the input shaft to the output shaft, and a cover that covers the transmission mechanism And a driving force transmission device having a pressure adjustment function for adjusting the pressure in the cover,
The transmission mechanism is
A clutch mechanism in which the output shaft is coupled to a shaft center portion, and a driving force input to the input shaft can be intermittently output to the output shaft;
A piston that generates a pressing force that causes the clutch mechanism to transition to a state in which the driving force input to the input shaft is output to the output shaft;
A protruding piece formed to protrude outward from the outer edge of the piston;
A fixing member that is fixed along the outer edge of the piston and that has the insertion piece inserted into the protruding piece, and that restricts the rotation of the protruding piece by the insertion portion;
A driving force transmission device comprising a communication hole formed in an inner wall of the cover member and corresponding to the insertion portion of the restriction member, and communicating the inside and the outside of the cover. The communication hole is located at a substantially center of the insertion portion in a first direction corresponding to the rotation direction of the output shaft,
The driving force transmission device according to claim 1, wherein the length of the protruding piece in the first direction is not less than half of the width of the insertion portion in the first direction.   3. The insertion portion, the protruding piece, and the communication hole are located at a position deviating from a vertical line passing through the axis of the output shaft and above the output shaft. The driving force transmission device according to 1. The cover is formed with a piston housing portion that houses at least an end portion of the piston on the side opposite to the clutch mechanism,
4. The driving force transmission device according to claim 1, wherein the protruding piece is formed at an end portion on the clutch mechanism side and is located outside the piston housing portion. 5. A pressing member that transmits a pressing force generated by the extension operation of the piston to the clutch mechanism;
The piston is formed in a substantially cylindrical shape, and the distance from the axis of the output shaft to the maximum diameter is longer than the distance from the axis of the output shaft to the farthest position of the pressing member. The driving force transmission device according to claim 4, wherein the driving force transmission device is configured as follows.

Images