JP2017186970A - Hydraulic pump unit for clutch working oil supply - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic pump unit for a hydraulic clutch working oil supply configured to keep start-up speed of working oil pressure excellent even in a case where an engine rotational frequency is low.SOLUTION: A hydraulic pump unit for clutch working oil supply is configured to supply discharged oil from a first hydraulic pump to a working oil chamber of a hydraulic clutch, regardless of a rotation speed of a power source. When the rotation speed of the power source is less than a predetermined value, discharged oil from a second hydraulic pump is confluent with the discharged oil from the first hydraulic pump. When the rotation speed of the power source is equal to or more than the predetermined value, the discharged oil from the second hydraulic pump is returned to a suction port of the first hydraulic pump.SELECTED DRAWING: Figure 12

Description

  The present invention relates to a hydraulic pump unit, and more particularly, to a hydraulic pump unit used for supplying hydraulic oil to a hydraulic clutch of a dual clutch transmission.

  2. Description of the Related Art Conventionally, as disclosed in, for example, Patent Document 1, a transport vehicle including a dual clutch transmission, that is, a so-called utility vehicle is known. The dual clutch transmission is a transmission case in which an odd speed (first speed, third speed, etc.) gear train including at least one odd gear train, and an even speed (first gear including at least one even gear train). (Second speed, fourth speed, etc.) gear train group, first clutch used for connection / disconnection of power transmission via odd speed gear train selected from the odd speed gear train group, and even speed gear train group A second clutch used for connecting / disconnecting power transmission via an even-numbered gear train that is more selectively selected is built in, and the first clutch and the second clutch are alternately engaged / separated. (I.e., when one engages the other, the other moves away), and while the power is transmitted without interruption, smooth gear shifting is possible from the first speed to the second speed and from the second speed to the third speed. realizable. In particular, during the transition of engagement / separation between the first clutch and the second clutch, both clutches are in a half-clutch state, thereby enabling a smooth gear shift.

  As such first and second clutches, hydraulic clutches that are easy to reveal a half-clutch state are used. Further, the dual clutch transmission disclosed in Patent Document 1 includes a dual hydraulic pump. The two hydraulic pumps constituting the dual hydraulic pump are simultaneously driven by an engine which is a drive source of the dual clutch transmission, and the discharge oil from one of these hydraulic pumps is the first It is supplied as hydraulic oil for the second clutch, hydraulic oil for the gear shifter switching actuator, and lubricating oil for each part. The oil discharged from the other hydraulic pump is supplied for other uses.

  The hydraulic pump (one hydraulic pump of the dual hydraulic pumps) used for the supply of hydraulic clutch hydraulic oil (hydraulic oil system) and the supply of lubricating oil (lubricating oil system) in Patent Document 1 The discharge amount increases in proportion to the above, and a large capacity is required. On the other hand, the amount of oil necessary for the lubricating oil system is defined by the relief pressure of the relief valve, etc., and does not increase in proportion to the engine speed. For this reason, most of the amount of oil discharged from the hydraulic pump during high-speed rotation of the engine is discharged in excess of the amount required as lubricating oil, resulting in a large energy loss and a vehicle running economy. It was not preferable.

  Therefore, it is conceivable to use a variable displacement hydraulic pump as a hydraulic pump for the hydraulic oil system and the lubricating oil system as described above so that the discharge amount can be adjusted without causing such an energy loss. For example, Patent Document 2 uses a vane pump capable of adjusting the amount of discharged oil by adjusting the amount of eccentricity of the cam ring by hydraulic control, as such a variable displacement hydraulic pump for hydraulic and lubricating oil systems. Yes.

JP 2008-309325 A JP-A-2-283958

  However, the variable displacement hydraulic pump as described above requires a hydraulic circuit for controlling the amount of discharged oil in addition to the hydraulic circuit for suction and discharge thereof. The structure is complicated and the manufacturing cost is likely to increase.

  The present invention, as a hydraulic pump unit for supplying hydraulic oil to a hydraulic clutch as used in a dual clutch transmission, consumes as much energy as possible when the engine as a power source rotates at high speed in view of the above situation. An object of the present invention is to provide a simple and low-cost structure capable of minimizing the work amount of the hydraulic pump.

  The present invention is a clutch hydraulic oil supply hydraulic pump unit that is a combination of two first hydraulic pumps and a second hydraulic pump that are simultaneously driven by a power source. Technical measures.

  In other words, the hydraulic pump unit for supplying clutch hydraulic oil according to the present invention supplies the oil discharged from the first hydraulic pump to the hydraulic oil chamber of the hydraulic clutch regardless of the rotational speed of the power source. When the rotation speed of the power source is less than a predetermined value, the discharge oil from the second hydraulic pump is merged with the discharge oil from the first hydraulic pump, and when the rotation speed of the power source is equal to or higher than the predetermined value, The discharge oil from the two hydraulic pumps is configured to return to the suction port of the first hydraulic pump.

  The hydraulic pump unit is extended from the discharge port of the first hydraulic pump, and is operated by a controller based on detection of the hydraulic oil supply oil path toward the hydraulic oil chamber of the hydraulic clutch and the rotational speed of the power source. An on-off valve controlled to open and close; a discharge port of the second hydraulic pump; a communication oil path connecting the hydraulic oil supply oil path to an inlet port of the on-off valve; and an outlet port of the on-off valve from the second hydraulic pump And a suction oil passage that communicates the suction ports of the first hydraulic pump and the second hydraulic pump with each other. The on-off valve is closed when the rotational speed of the power source is less than a predetermined value, and oil from the discharge port of the second hydraulic pump is supplied to the hydraulic oil supply oil passage through the communication oil passage. To join. The on-off valve is opened when the rotational speed of the power source is equal to or higher than a predetermined value, and oil from the discharge port of the second hydraulic pump to the communication oil passage is supplied from the inlet port to the outlet port. And return to the suction port of the first hydraulic pump through the return oil passage, the suction port of the second hydraulic pump, and the suction oil passage.

  Further, a check valve that allows only an oil flow from the communication oil path to the hydraulic oil supply oil path when the on-off valve is closed between the communication oil path and the hydraulic oil supply oil path. Provided.

  As described above, the hydraulic pump unit for supplying the clutch hydraulic oil according to the present invention supplies the hydraulic oil discharged from both the first and second hydraulic pumps to the hydraulic oil supply oil passage when the rotational speed of the power source is less than a predetermined value. By feeding in, the supply amount of hydraulic oil required for the operation of the hydraulic clutch and the supply amount of lubricating oil required for a transmission mechanism such as a dual clutch transmission are secured, while the rotational speed of the power source Since only the oil discharged from the first hydraulic pump is supplied as the hydraulic oil for the hydraulic clutch during high-speed rotation of the power source where the power is in the region above the predetermined value, the amount of discharged oil does not become excessive and is used for driving the hydraulic pump Energy can be minimized. Thus, fuel consumption can be improved by reducing the energy used for driving the hydraulic pump.

  In addition, as described above, the hydraulic oil supply oil path, the communication oil path, the return oil path, and the suction oil path are configured so that the hydraulic oil according to the rotational speed of the power source by the first and second hydraulic pumps as described above. A supply system can be realized. Such hydraulic oil supply oil passage, communication oil passage, return oil passage, and suction oil passage can be configured around the first and second hydraulic pumps and the on-off valve as a hydraulic pump unit. The compactness of the pump unit can be secured.

  Further, by providing the check valve as described above, the oil discharged from the first hydraulic pump does not leak into the communication oil passage with a simple configuration, and the oil amount can be switched reliably.

1 is a schematic side view of a transport vehicle as an embodiment of a work vehicle including a dual clutch transmission. 2 is a schematic plan view of the transport vehicle. It is a skeleton figure of a dual clutch transmission. FIG. 3 is a hydraulic circuit diagram showing a hydraulic oil supply system to hydraulic clutch units as first and second clutches in the dual clutch transmission. It is a front view of a dual clutch type transmission. FIG. 3 is a front view of the dual clutch transmission that shows a layout of gears in a clutch chamber by removing a lid. It is the front partial cross section part of the cover body removed from the housing of the said dual clutch transmission. 2 is a schematic front sectional view of the dual clutch transmission showing a layout of gears in a gear chamber. FIG. 9 is a developed cross-sectional view of the dual clutch transmission according to the XL line in FIG. 8. FIG. 10 is an enlarged cross-sectional view of a hydraulic clutch unit as a first clutch in the dual clutch transmission shown in FIG. 9. It is a perspective view of the lubricating oil guide plate used for the hydraulic clutch unit shown in FIG. FIG. 3 is a partial side cross-sectional view of the dual clutch transmission that shows an oil passage structure of a hydraulic pump unit and a transmission case disposed in the gear chamber. FIG. 5 is a partial side cross-sectional view of another type of dual clutch transmission in which a hydraulic pump unit is disposed in the clutch chamber. FIG. 14 is a correlation diagram of the pump discharge amount with respect to the engine speed, showing the effect of reducing the discharge oil amount using the hydraulic pump unit shown in FIG.

  A transport vehicle (so-called utility vehicle) 100 shown in FIGS. 1 and 2 will be described. The transport vehicle 100 includes a vehicle frame (chassis) 101 that extends in the front-rear direction from the front end to the rear end. The left and right rear wheels 110 are suspended at the rear of the vehicle frame 101 via the suspensions 119, while the left and right front wheels 120 are suspended at the front of the vehicle frame 101 via the suspensions 128. Has been.

  A loading platform mounting frame 102 is configured at the rear portion of the vehicle frame 101, and an engine E having a crankshaft in the front-rear direction is supported on the vehicle frame 101 in the loading platform mounting frame 102.

  A loading platform 107 is mounted on the loading platform mounting frame 102 so as to be rotatable upward. Normally, it turns upward as indicated by the phantom line in FIG. 1 for unloading or the like. However, when it is desired to access the engine E for maintenance or the like, the carrier 107 is turned upward in this way. Then, the engine E arranged below is opened and accessible.

  A seat base 103 is formed in the front part of the loading platform mounting frame 102, and a seat 108 is mounted on the seat base 103 as described later. Immediately before the seat base 103, a platform 104 is laid on the body frame 101, and serves as a foot board for a person sitting on the seat 108 when getting on and off the transport vehicle 100.

  A bonnet 105 is provided at the front of the vehicle body frame 101 in front of the platform 104, a front column 106 is formed at the rear end of the bonnet 105, and a steering handle 109 is provided above the front column 106. .

  In the space covered by the seat base 103, the dual clutch transmission 1 is disposed and supported by the vehicle frame 101. A horizontal engine output shaft Ea protrudes forward from the engine E, and a flywheel Eb is provided at the front end of the engine output shaft Ea.

  The dual clutch transmission 1 arranged in front of the engine E has a mission case 2 as a casing. A rear-open flywheel chamber 2a is formed in the rear part of the transmission case 2, and the flywheel Eb of the engine E is disposed in the flywheel chamber 2a.

  The dual clutch transmission 1 is configured by housing a gear mechanism and a clutch mechanism for shifting and a traveling direction switching, which will be described later, in a transmission case 2, and is used for power input to the gear mechanism and the clutch mechanism. The rear end of the input shaft 7 extends into the flywheel chamber 2a and is connected to the flywheel Eb.

  A seat 108 is mounted on a seat placement plate 103 a that forms the horizontal upper surface of the seat base 103. In this embodiment, a pair of left and right seats 108 are provided as a driver seat and a passenger seat. As described above, the dual clutch transmission disposed in the space in the seat base 103 is disposed below the seat 108 placed on the seat placement plate 103a.

  The seat placement plate 103a can be rotated forward together with the seat 108, as indicated by a virtual line in FIG. That is, the seat 108 is rotatably mounted on the seat base 103 via the seat mounting plate 103a, and is surrounded by the seat base 103 by rotating the seat 108 forward together with the seat mounting plate 103a. The open space is opened upward and access to the dual clutch transmission 1 can be made.

  The flywheel housing 3 having the flywheel chamber 2a formed therein is connected to the rear portion of the main housing 4, and the lid body 5 is attached to the front portion of the main housing 4, and thus the flywheel housing 3 joined back and forth. The main housing 4 and the lid 5 constitute the transmission case 2 of the dual clutch transmission 1 described above.

  Since the lid 5 is detachably attached to the main housing 4 at the front end portion of the mission case 2, as described above, the seat mounting plate 103a and the seat 108 are rotated forward so as to be a dual clutch type. When accessing the transmission 1, the lid 5 can be removed from the main housing 4, and a later-described clutch chamber 2 c formed in the front portion of the transmission case 2 can be opened forward. The first and second clutches 21 and 31 can be easily accessed.

  A rear axle driving device 112 for driving the rear wheels 110 is supported at the rear portion of the vehicle body frame 101. The rear axle drive device 112 has a rear axle drive case 113 and a typical bevel gear type differential gear mechanism 116 is accommodated in the rear axle drive case 113.

  The differential gear mechanism 116 connects the inner ends of the pair of left and right differential output shafts 117 so as to be differentially rotatable. Each of the rear wheels 110 protrudes outward and is connected to an axle 110a of each rear wheel 110 via a transmission shaft 118 with a universal joint.

  The rear axle drive device 112 has an input shaft 114 in the front-rear horizontal direction. The input shaft 114 is pivotally supported by a rear axle drive case 113, and a front end portion thereof protrudes from the rear axle drive case 113. On the other hand, the dual clutch transmission 1 supports a front / rear horizontal output shaft 12 in a mission case 2 (main housing 4), and a rear end portion of the output shaft 12 is provided at the rear outside of the mission case 2. It protrudes to the left and is connected to the input shaft 114 of the rear axle drive device 112.

  The input shaft 114 is disposed on the same axis with respect to the output shaft 12. Between the rear end of the output shaft 12 and the front end of the input shaft 114, a transmission shaft 111 in the front-rear and horizontal directions is provided on the same axis, and couplings 111a and 111b made of spline cylinders or the like are provided. The front end of the transmission shaft 111 is connected to the rear end of the output shaft 12, and the rear end of the transmission shaft 111 is connected to the front end of the input shaft 114, and the output shaft 12, the transmission shaft 111, and the input on the same axis are connected. The shaft 114 is coupled so as to be integrally rotatable (relatively impossible). With such a connecting structure from the output shaft 12 to the input shaft 114 on the same shaft core, a high transmission efficiency from the output shaft 12 to the rear wheel 110 is secured, and the driving efficiency of the rear wheel 110 is increased.

  It should be noted that the shaft support position of the output shaft 12 in the transmission case 2 (main housing 4) is slightly biased in the left-right direction of the transport vehicle 100 from the left-right center (rightward in this embodiment). On the other hand, the differential gear mechanism 116 in the rear axle driving device 112 is disposed at the substantially left and right center of the transport vehicle 100 so that the distance in the left-right direction to the left and right rear wheels 110 is equal.

  Therefore, the input shaft 114 disposed on the same axis with respect to the output shaft 12 of the dual clutch transmission 1 is offset from the differential gear mechanism 116 in the left-right direction. A horizontal counter shaft 115 is pivotally supported in the front portion of the rear axle drive case 113 (in front of the differential gear mechanism 115) so as to fill in the lateral displacement.

  In the rear axle drive case 113, a bevel gear 115a is fixed (or formed) at one end (right end in this embodiment) of the counter shaft 115, and is fixed (or formed) at the rear end of the input shaft 114. Is engaged with the bevel gear 114a. On the other hand, a flat gear 115b is fixed (or formed) to the other end (the left end in the present embodiment) of the counter shaft 115, and meshes with a flat gear as the input gear 116a of the differential gear mechanism 116. ing.

  A rear axle driving device 122 for driving the front wheels 120 is supported on the front portion of the body frame 101. The front axle drive device 122 has a front axle drive case 123 and accommodates a usual bevel gear type differential gear mechanism 125 in the front axle drive case 123.

  The differential gear mechanism 125 connects the inner ends of the pair of left and right differential output shafts 126 so as to be differentially rotatable. It protrudes outward and is connected to the axle 120a of each front wheel 120 via a transmission shaft 127 with a universal joint.

  The left and right front wheels 120 are steering wheels, and both front wheels 120 are connected to each other by tie rods 129. The tie rods 129 move to the left and right according to the turning operation of the steering handle 109, so that both front wheels 120 are simultaneously turned to the left and right. It is assumed that the transport vehicle 100 turns and turns.

  The front axle drive device 122 has a front / rear horizontal input shaft 124. The input shaft 124 is pivotally supported at the rear portion of the rear axle drive case 123, and a bevel gear 124a fixed (or formed) at the front end of the input shaft 124 in the front axle drive case 123 is replaced with a differential gear mechanism. 125 meshes with a bevel gear as an input gear 125a.

  The rear end portion of the input shaft 124 projects rearward from the front axle drive case 123. On the other hand, in the dual clutch transmission 1, the front end portion of the output shaft 12 is in front of the transmission case 2 (main housing 4). It protrudes to the outside. A transmission shaft 121 is interposed between the front end of the output shaft 12 and the front end of the input shaft 124. The rear end of the transmission shaft 121 is connected to the front end of the output shaft 12 through universal joints 121a and 121b. The front end of the transmission shaft 121 is connected to the rear end of the input shaft 124.

  While the input shaft 124 and the differential gear mechanism 125 of the front axle driving device 122 are disposed at the substantially right and left center of the transport vehicle 100, the output shaft 12 of the dual clutch transmission 1 is the left and right of the transport vehicle 100 as described above. Since it is slightly shifted to one side (right side in this embodiment), the transmission shaft 121 interposed between the output shaft 12 and the input shaft 124 is inclined to the left and right, and at the universal joints 121a and 121b, Power transmission from the output shaft 12 to the input shaft 124 via the inclined transmission shaft 121 is ensured.

  Next, the power transmission system from the input shaft 7 to the output shaft 12 constituting the dual clutch transmission 1 will be described with reference to the skeleton diagram of FIG. 3 and the structural diagram of FIG.

  The dual clutch transmission 1 is parallel to the front / rear horizontal input shaft 7 and the front / rear horizontal output shaft 12 parallel to the input shaft 7 disposed on the same axis with respect to the output shaft Ea of the engine E. It has a first clutch shaft 8, a second clutch shaft 9, a speed change driven shaft 10, and a counter shaft 11 in the front-rear horizontal direction.

  The input shaft 7 is connected to the engine output shaft Ea via the flywheel Eb as described above. An input gear 7a, which is a flat gear, is fixed (or formed) to the input shaft 7, and a first clutch gear 20, which is a flat gear loosely fitted to the first clutch shaft 8, and the first gear 7a, The second clutch gear 30, which is a flat gear loosely fitted to the two clutch shaft 9, is meshed. As described above, the first clutch gear 20 and the second clutch gear 30 are both meshed with the input gear 7a, but the first clutch gear 20 and the second clutch gear 30 are not meshed with each other.

  In addition, as for the engine E that is a power source of the dual clutch transmission 1, there are several types of engines with different types (gasoline engine or diesel engine) and specifications (displacement etc.) mounted on the vehicle. The size of the input gear 7a and the first and second clutch gears 20 and 30 of the dual clutch transmission 1 is changed to accommodate the difference in the rotational speed of the engine output shaft Ea connected to the input shaft 7. By doing so, the gear ratio is adjusted.

  A first clutch 21 is provided on the first clutch shaft 8, and the power from the input shaft 7 received by the first clutch gear 20 is transmitted to the first clutch shaft 8 by engaging the first clutch 21. It is said. On the other hand, the second clutch shaft 9 is provided with a second clutch 31, and the power from the input shaft 7 received by the second clutch gear 30 is transmitted to the second clutch shaft 9 by engaging the second clutch 31. I am going to do it.

  As will be described later, as the first and second clutches 21 and 31, the clutch engagement pressure is set by an electromagnetic proportional valve from zero to a predetermined pressure when the clutch is engaged, or from a predetermined pressure to zero when the clutch is disengaged. A proportionally controlled hydraulic clutch unit 60 is used, and unlike a meshing clutch described later, a moderate clutch engagement state (so-called half-clutch) can be achieved.

  The first clutch shaft 8 is provided with a first speed (lowest speed) drive gear 22, a third speed drive gear 24, and a fifth speed (highest speed) drive gear 26, each of which is provided on the variable speed driven shaft 10. The first speed (minimum speed) driven gear 23, the third speed driven gear 25, and the fifth speed driven gear 27 are directly meshed with each other.

  Thus, a first speed (lowest speed) gear train G1a composed of the first speed drive gear 22 and the first speed driven gear 23, a third speed gear train G1b composed of the third speed drive gear 24 and the third speed driven gear 25, The fifth speed (highest speed) gear train G1c composed of the fifth speed drive gear 26 and the fifth speed driven gear 27 is combined, and the odd speed gear train for transmitting power from the first clutch shaft 8 to the transmission driven shaft 10. Group G1.

  As long as the first clutch 21 is engaged, via a gear train selected from the first gear, third gear, fifth gear train G1a, G1b, and G1c in the odd-speed gear train group G1. The power is transmitted from the first clutch shaft 8 to the speed change driven shaft 10. Shifters 28 and 29 are provided as members for selecting a gear train to be subjected to power transmission from the odd speed gear train group G1.

  Here, in the first speed gear train G1a and the third gear train G1b, the first speed drive gear 22 and the third speed drive gear 24 are provided on the first clutch shaft 8 so as not to rotate relative to each other (in this embodiment, As shown in FIG. 8, the first speed drive gear 22 is formed on the first clutch shaft 8 and the third speed drive gear 24 is fixed to the first clutch shaft 8), and the first speed driven gear 23 and The third speed driven gear 25 is loosely fitted to the speed change driven shaft 10 (relatively rotatable with respect to the speed change driven shaft 10).

  Corresponding to these first and third speed gear trains G1a and G1b, the shifter 28 is not rotatable relative to the speed change driven shaft 10 between the first speed driven gear 23 and the third speed driven gear 25. In addition, it is slidable in the axial direction (front-rear direction). Clutch teeth are respectively formed on the first speed driven gear 23 and the third speed driven gear 25, and clutch teeth that can be engaged with the gears 23 and 25 are formed on each end face of the shifter 28. That is, the shifter 28 and the first speed driven gear 23 constitute a meshing clutch, and the shifter 28 and the third speed gear train 25 constitute a meshing clutch on the opposite side in the axial direction.

  The shifter 28 slides along the variable speed driven shaft 10 so that the first speed position where the clutch engages only with the first speed driven gear 23 and the third speed position where only the third speed driven gear 25 engages with the clutch. The first speed driven gear 23 and the third speed driven gear 25 are switched to the neutral position where they are not engaged.

  In the fifth speed gear train G1c, the fifth speed drive gear 26 is loosely fitted to the first clutch shaft 8 (relatively rotatable with respect to the first clutch shaft 8), and the fifth speed driven gear 27 is shifted. It cannot rotate relative to the driven shaft 10 (fixed to the variable speed driven shaft 10). Corresponding to such a fifth speed gear train G1c, a shifter 29 is provided on the first clutch shaft 8 so as not to be relatively rotatable and to be slidable in the axial direction (front-rear direction). Clutch teeth are formed on the fifth speed driven gear 26 and the shifter 29 so as to be engageable with each other, and the shifter 29 and the fifth speed driven gear 26 constitute a meshing clutch.

  The shifter 29 slides along the first clutch shaft 8 so that the shifter 29 has two positions, a fifth speed position where the fifth speed driven gear 26 is engaged with the clutch and a neutral position where the fifth speed driven gear 26 is not engaged. Can be switched to.

  The second clutch shaft 9 is provided with a second speed drive gear 32 and a fourth speed drive gear 34, respectively, and a second speed driven gear 33 and a fourth speed driven gear 35 provided on the transmission driven shaft 10, respectively. Direct meshing.

  Thus, the second speed gear train G2a composed of the second speed drive gear 32 and the second speed driven gear 33 and the fourth speed gear train G2b composed of the fourth speed drive gear 34 and the fourth speed driven gear 35 are combined. An even-speed gear train group G2 for transmitting power from the second clutch shaft 9 to the transmission driven shaft 10 is used.

  As long as the second clutch 31 is engaged, the second clutch shaft is connected via a gear train selected from the second gear train G2a and the fourth gear train G2b in the even gear train group G2. Power is transmitted from 9 to the variable speed driven shaft 10. A shifter 36 is provided as a member for selecting a gear train for power transmission from the even-speed gear train group G2.

  Here, in the second speed gear train G2a and the fourth gear train G2b, the second speed drive gear 32 and the fourth speed drive gear 34 are provided so as not to rotate relative to the second clutch shaft 9 (both are the first gear train). The second speed driven gear 33 and the fourth speed driven gear 35 are loosely fitted on the speed change driven shaft 10 (relatively rotatable with respect to the speed change driven shaft 10).

  Corresponding to these second speed / fourth speed gear trains G2a, G2b, the shifter 36 cannot be rotated relative to the transmission driven shaft 10 between the second speed driven gear 33 and the fourth speed driven gear 35. In addition, it is slidable in the axial direction (front-rear direction). Clutch teeth are formed on the second speed driven gear 33 and the fourth speed driven gear 35, respectively, and clutch teeth that can be engaged with the gears 33 and 35 are formed on each end face of the shifter 36. That is, the shifter 36 and the second speed driven gear 33 constitute a meshing clutch, and the shifter 36 and the fourth speed gear train 35 constitute a meshing clutch on the opposite side in the axial direction.

  The shifter 36 slides along the speed change driven shaft 10 so that the second speed position where only the second speed driven gear 33 is engaged with the clutch, and the fourth speed position where only the fourth speed driven gear 35 is engaged with the clutch. , The second speed driven gear 33 and the fourth speed driven gear 35 are switched to the neutral position where they are not engaged.

  The forward drive gear 41 fixed (or formed) on the variable speed driven shaft 10 and the forward driven gear 42 fixed (or formed) on the counter shaft 11 are engaged with each other, and the forward gear composed of the gears 41 and 42 is engaged. A column G3 is configured.

  On the other hand, a reverse drive gear 43 fixed (or formed) on the second clutch shaft 9 meshes with a reverse driven gear 44 loosely fitted on the counter shaft 11 (which is rotatable relative to the counter shaft 11). , A reverse gear train G4 including the gears 43 and 44 is configured.

  Preferably, the forward driven gear 42 in the forward gear train G3 has a larger diameter than the forward drive gear 41, the forward gear train G3 is a reduction gear train, and the reverse driven gear 44 in the reverse gear train G4 is a reverse drive gear. The reverse gear train G4 is a reduction gear train with a larger diameter than 43, and the gear ratios of the reverse gear train and the forward gear train may be set as appropriate. You may comprise as.

  A shifter 45 is fitted to the counter shaft 11 so as not to rotate relative to the counter shaft 11 and to be slidable in the axial direction (front-rear). Clutch teeth that can mesh with each other are formed on the shifter 45 and the reverse driven gear 44, and the shifter 45 and the reverse driven gear 44 constitute a meshing clutch. By shifting along the counter shaft 10, the shifter 45 is switched between a reverse position where the reverse driven gear 44 is engaged with the clutch and a neutral position (or a forward position) which is separated from the reverse driven gear 44.

  A small diameter gear 46 is fixed (or formed) to the counter shaft 11, and a large diameter gear 47 is fixed (or formed) to the output shaft 11, and the small diameter gear 46 and the large diameter gear 47 are engaged with each other. A final reduction gear train G5 consisting of 47 is constructed. Depending on the design, the gear train interposed between the counter shaft 11 and the output shaft 12 may be a constant speed gear train or a speed increasing gear train.

  Here, since each of the first clutch gear 20 and the second clutch gear 30 meshes with the input gear 7a of the input shaft 7, the first clutch 21 is engaged and driven by receiving the rotational power of the input shaft 7. The rotation direction of the first clutch shaft 8 is the same as the rotation direction of the second clutch shaft 9 that is driven by receiving the rotational power of the input shaft 7 by engaging the second clutch 31. Therefore, regardless of whether the speed gear train receiving the power is of the odd speed gear train group G1 or the even speed gear train group G2, the rotational direction of the transmission driven shaft 10 is constant, The direction is opposite to that of the first clutch shaft 8 and the second clutch shaft 9. On the other hand, the rotational direction of the counter shaft 11 when driven by receiving power from the second clutch shaft 9 via the gears 43 and 44 of the reverse gear train G4 is opposite to the rotational direction of the second clutch shaft 9.

  When the vehicle is stopped, the shift operation tool (not shown) provided near the seat 108 of the transport vehicle 100 (for example, the front column 106) is in the neutral position, and both the clutches 21 and 31 are disconnected, but the shifter 28 is In the first speed position, the shifter 45 is in the reverse position.

  When the operation tool is put in the forward first speed position, the controller controls the electromagnetic proportional valve 71 to gradually increase the engagement pressure in the first clutch 21 from zero to a predetermined pressure, and to bring the first clutch 21 into the half-clutch state. To complete engagement via. When the operation tool is put in the reverse drive position, the controller controls the electromagnetic proportional valve 72 to gradually increase the engagement pressure in the second clutch 31 from zero to a predetermined pressure, and route the second clutch 31 through the half-clutch state. Bring to full engagement.

  And when operating this operation tool in the second forward speed, when the shifter 45 is placed in the neutral position and the shifter 36 is in the second forward speed position in advance, Almost simultaneously with the start of reducing the engagement pressure of the first clutch 21, the application of the engagement pressure to the second clutch 31, which has been separated, is started, and the transition from the engagement state of the first clutch 21 to the half-clutch state is started. In parallel, the second clutch 31 is shifted from the disengaged state to the half-clutch state.

  Thus, by increasing the transmission power from the second clutch shaft 9 to the transmission driven shaft 10 via the second speed gear train G2a, the shifter 28 is held at the first speed position and the shifter 36 is held at the second speed position. The forward speed can be smoothly shifted from the first speed to the second speed. Eventually, the engagement of the second clutch 21 is completed, the separation of the first clutch 31 is completed, and the drive of the speed change driven shaft 10 is completely driven from the second clutch shaft 9 via the second speed gear train G2a. It will be due to.

  Next, when shifting up from the second speed to the third speed, the shifter 28 is shifted to the third speed position so that the shifters 29 and 45 are in the neutral position and the shifter 36 is in the second speed position. The first clutch 21 may be engaged while separating the second clutch 31.

  In addition, a hydraulic pump set 50 including a pair of fixed displacement gear pumps 50a and 50b is accommodated in the transmission case 2, and a pump as a drive shaft of the gear pumps 50a and 50b of the hydraulic pump set 50 is accommodated. The drive shaft 14 is supported in the front-rear horizontal direction in the vicinity of the input shaft 7 in parallel with the input shaft 7.

  A flat gear 7b fixed (or formed) on the input shaft 7 and a flat gear 14a fixed (or formed) on the pump drive shaft 14 mesh with each other, and the input shaft 7 to the pump drive shaft 14 are engaged. The power is transmitted. In other words, the rotational power of the input shaft 7 is distributed to the first clutch shaft 8 and the second clutch shaft 9 as travel driving power for driving the output shaft 12, and in parallel therewith, the hydraulic pump set 50 It is distributed to the pump drive shaft 14 as power for driving the pump for driving the gear pumps 50a and 50b.

  Next, the configuration of the mission case 2 and the layout of the components constituting the clutch mechanism and gear mechanism described above inside and outside the mission case 2 will be described with reference to FIGS.

  In describing these layouts, regarding the position and direction of the dual clutch transmission 1, the dual clutch transmission 1 is disposed in front of the engine 103 in the transport vehicle 100 as described above. 7 and the output shaft 12 are assumed to extend in the front-rear horizontal direction. That is, it should be noted that the left and right positions are described on the premise that the transport vehicle 100 is directed in the forward direction, and thus opposite to the left and right positions in front view shown in FIGS. 5 to 8.

  As described above, the mission case 2 is configured by joining the flywheel housing 3 to the rear part of the main housing 4 and joining the lid 5 to the front part of the main housing 4. A flange edge 4 a having a bolt boss is formed over the entire periphery of the rear end of the main housing 4. The flange edge 4 a is in contact with the flange edge 3 a formed over the entire periphery of the front opening of the flywheel housing 3. The flywheel housing 3 and the main housing 4 are detachably joined to each other by fastening the flange edges 3a and 4a.

  On the other hand, as shown in FIG. 4, an opening is provided in a part of the front end portion of the main housing 4, and a front end edge 4b is formed so as to surround the opening. A flange edge 5a having a bolt boss formed over the entire circumference of the rear end of the opening of the lid 5 is brought into contact with the front edge 4b, and the bolt 6 is screwed into each bolt boss formed on the flange edge 5a. The housing 4 and the lid 5 are fastened so as to be separable.

  A substantially vertical bearing wall 3 b is formed in the flywheel housing 3, and the rear portion of the input shaft 7, the first clutch shaft 8, the second clutch shaft 9, and the transmission driven shaft are formed by the bearing wall 3 b. 10, the counter shaft 11 and the rear end of the pump drive shaft 14 are pivotally supported via respective bearings. In the flywheel housing 3, the flywheel chamber 2a is formed behind the bearing wall 3b as described above.

  A flywheel chamber 2a is opened rearward at the rear end of the flywheel housing 3. By connecting the rear end of the flywheel housing 3 to the engine E, the flywheel chamber 2a has an engine output shaft Ea. A flywheel Eb at the front end is arranged. Correspondingly, the rear end portion of the input shaft 7 extends rearward from the bearing wall 3b, and is substantially on the same axis as the engine output shaft Ea via the flywheel Eb in the flywheel chamber 2a. Connected at.

  A vertical bearing wall 4c is formed immediately after the front edge 4b of the main housing 4, and the input shaft 7, the first clutch shaft 8, and the second clutch shaft 9 are formed on the bearing wall 4c. Each front part, and each front end of the speed change driven shaft 10 and the counter shaft 11 are pivotally supported via each bearing.

  A cavity as a gear chamber 2b is formed in the main housing 4 behind the bearing wall 4c, that is, closer to the engine E. The bearing wall 3b of the flywheel housing 3 is the rear end of the gear chamber 2b. Is drawn. In the gear chamber 2b, the odd speed gear train group G1, the even speed gear train group G2, the forward gear train G3, the reverse gear train G4, the final reduction gear train G5, and a shifter used for power transmission control thereof. 28, 29, 36, 45 etc. are accommodated.

  The odd-numbered gear train group G1, the even-speed gear train group G2 and the like described above are disposed in a portion of the gear chamber 2b sandwiched between the front and rear bearing walls 3b and 4c. The flange edge 3a at the front end of the flywheel housing 3 and the main housing 4 joined thereto are expanded further to the left and right sides (right side in this embodiment) with respect to the portions forming the bearing walls 3a and 4c. In the gear chamber 2b, an extended portion 2b1 (see FIG. 8) is formed that extends further to the left and right sides (right side in this embodiment) from the portion sandwiched between the bearing walls 3b and 4c.

  The output shaft 12 is disposed in the extended portion 2b1 of the gear chamber 2b. The front portion of the output shaft 12 is pivotally supported via a bearing at the wall portion of the main housing 4 that defines the front end of the expansion portion 2b1, and from here, the output shaft 12 coupled to the transmission shaft 121 is supported. The front end protrudes forward. On the other hand, the rear portion of the output shaft 12 is pivotally supported via a bearing at the wall portion of the flywheel housing 3 that defines the rear end of the expansion portion 2b1, and the output connected to the transmission shaft 111 from here is supported. The rear end portion of the shaft 12 protrudes rearward.

  Further, as can be seen in FIGS. 8 and 9, a parking brake shaft 13 is disposed on the left and right outer sides (right side in the present embodiment) of the output shaft 12 in the extended portion 2 b 1. Is supported by the wall portion of the main housing 4, while the rear end portion projects rearward from the flywheel housing 3, and an arm 13a is fixed to the rear end portion.

  In the extended portion 2b1 of the gear chamber 2b, the lower end portion of the parking pawl member 48 is fixed to the parking brake shaft 13, and the parking pawl member 48 extends upward in the form of an arm from the lower end portion. A latch claw 48 a for meshing with the gear teeth of the large-diameter gear 47 is formed on the upper part. A long hole is formed in the upper and lower intermediate portion of the parking claw member 48 between the lower end portion fixed to the parking brake shaft 13 and the latch claw 48a formed at the upper portion. In addition, an eccentric cam 48b is fitted.

  The arm 13a is linked to a parking brake operation tool (not shown) such as a lever and a pedal provided near the seat 108 of the transport vehicle by a link mechanism (not shown). By rotating the eccentric cam 48b by operating this operation tool, the parking brake shaft 13 is rotated, and a latch claw 48a formed in a sawtooth shape on the parking claw member 48 is fixed to the output shaft 12. The parking position for engaging with the gear teeth of the diameter gear 47 and the parking release position for separating the latch pawl 48a from the large diameter gear 47 are switched.

  As can be seen in FIG. 9, a vertical bearing wall 4c is formed in the main housing 4 at a position immediately behind the front end edge 4b, and the front end of the variable speed driven shaft 10 is formed on the bearing wall 4c. It is pivotally supported via a bearing.

  The bearing wall 4c is a partition wall that partitions the rear gear chamber 2b and the front clutch chamber 2c. The bearing wall 4c includes the input shaft 7, the first clutch shaft 8, and the second clutch shaft 9. Are inserted and pivotally supported through the respective bearings, and the front end portion of the input shaft 7 and the front portions of the first clutch shaft 8 and the second clutch shaft 9 are arranged in the clutch chamber 2c. The bearing wall 4c defines the rear end of the clutch chamber 2c. On the other hand, the flange edge 5a is fastened to the front end edge 4b of the main housing 4 via the bolt 6 as described above, so that the front end of the main housing 4 is secured. The inner surface (rear surface) of the attached lid 5 defines the front end of the clutch chamber 2c.

  The front end portion of the input shaft 7 is disposed immediately before the bearing wall 4c at the rear end of the clutch chamber 2c, and the input gear 7a is fixed thereto, and the first clutch gear on the first clutch shaft 8 meshing with the input gear 7a. 20 and the second clutch gear 30 on the second clutch shaft 9 are also provided immediately before the bearing wall 4c.

  Here, in FIG. 8, the shafts of the input shaft 7, the first clutch shaft 8, the second clutch shaft 9, the transmission driven shaft 10, the counter shaft 11, the output shaft 12, and the pump drive shaft 14 in the front view, Reference numerals 7X, 8X, 9X, 10X, 11X, 12X, and 14X are shown.

  In FIG. 8, the shaft core 14X of the pump drive shaft, the shaft core 7X of the input shaft, the shaft core 8X of the first clutch shaft, the shaft core 10X of the speed change driven shaft, the shaft core 9X of the second clutch shaft, the shaft of the counter shaft A virtual line XL formed by connecting the core 11X and the shaft core 12X of the output shaft in order is shown. It can be seen that the virtual line XL is a zigzag broken line.

  Thus, by arranging these axes so that the shaft cores are arranged in a zigzag shape in front view, the arrangement space of these axes is prevented from expanding in the left-right direction and the up-down direction. The overall compact case 2 can be reduced in the left-right direction and the up-down direction due to the compact arrangement of the shafts as a whole.

  Here, since the position of the axis 7X of the input shaft 7 needs to be arranged on the same axis with respect to the output shaft Ea of the engine E, the vertical position is restricted, and the position is relatively low in the mission case 2. Arranged.

  On the other hand, as the first clutch 21 on the first clutch shaft 8 and the second clutch 31 on the second clutch shaft 9, a hydraulic clutch unit 60 (see FIG. 10) as will be described later is used, and its hydraulic oil supply In this case, since the fine control of the engagement pressure is required as described above, the electromagnetic proportional valves 71 and 72 are used. These electromagnetic proportional valves 71 and 72 are preferably arranged in the vicinity of the respective clutches 21 and 31 to be controlled. On the other hand, when the electromagnetic proportional valves 71 and 72 are arranged at a position lower than the input shaft 7 at a relatively low position as described above. Considering that the vehicle runs through the wetland, there is a difficulty in waterproofing the solenoid coil.

  Therefore, as shown in FIGS. 6 and 8, first, one of the first and second clutch shafts 8, 9 is set to a height approximately equal to that of the input shaft 7 and left and right of the input shaft 7. The other shaft is disposed above the input shaft 7. In this embodiment, the output shaft 12 is arranged on the right side of the input shaft 7 (left side in FIGS. 6 and 8 in front view), and the second clutch is opposed to the counter shaft 11 arranged in the vicinity of the output shaft 12. Since the shaft 9 is linked by the reverse gear train G4 (gears 43 and 44) without passing through the speed change driven shaft 10, the second clutch shaft 9 is connected to the right side of the input shaft 7 (in the left-right direction with the input shaft 7). The first clutch shaft 8 is disposed above the input shaft 7.

  With such an arrangement, the first clutch shafts 8 and 9 are arranged at a height suitable for the electromagnetic proportional valves 71 and 72. Further, as shown in FIG. 8, in front view, the shaft core 8X of the first clutch shaft 8 and the shaft core 9X of the second clutch shaft 9 are arranged obliquely in the vertical and horizontal directions. As can be seen from the fact that the first clutch gear 20 and the second clutch gear 30 are arranged obliquely in the vertical and horizontal directions, the first clutch 21 and the second clutch 31 are viewed in the axial direction. Since the first clutch 21 is arranged obliquely in the vertical and horizontal directions (that is, the first clutch 21 is arranged at the upper left of the second clutch 31), as can be seen from the layout in front view, In the side view, the lower part of the first clutch 21 and the upper part of the second clutch 31 overlap, while in the plan view outside the figure, the right part of the first clutch 21 and the left part of the second clutch 31 overlap.・ Second clutch 21 ・ 31 It has shrunk in the vertical and horizontal directions of space required location.

  Further, as shown in FIG. 8, due to the oblique arrangement of the first and second clutch shafts 8 and 9, in the gear chamber 2b, on the right side of the first clutch shaft 8 and on the upper side of the second clutch shaft 9. Space is secured, and the odd speed gear train group G1 and the even speed gear train group G2 as a whole are compactly arranged at a relatively high position in the gear chamber 2b by arranging the speed change driven shaft 10 here. Can do.

  The counter shaft 11 is arranged on the right side of the speed change driven shaft 10, the output shaft 12 is arranged below the counter shaft 11, and the forward gear train G3 (gears 41 and 42) and the final reduction gear train G5 (46 and 47) are arranged. The odd-numbered gear train group G1 and the even-speed gear train group G2 are arranged at substantially the same height on the right side.

  As described above, the odd-numbered gear train group G1, the even-speed gear train group G2, the forward gear train G3, the reverse gear train G4, and the final reduction gear train G5 are kept in the gear chamber 2b so as not to be lower than the input shaft 7. 8 except that the lower part of the large-diameter gear 47 is immersed in an oil sump in the lower part of the gear chamber 2b, as shown in FIG. The gear mechanism of the dual clutch transmission 1 is configured to have a high transmission efficiency because it is disposed higher than the surface FL and has little oil pool agitation resistance.

  Even if substantially all the gears are arranged higher than the oil level FL as described above, by arranging the shafts constituting these gears in a zigzag manner as described above, the entire gears can be moved vertically. And in right and left, it is accommodated in the gear chamber 2b in a compact state.

  On the other hand, the clutch chamber 2c is first and second provided in front of the first and second clutch shafts 8 and 9 constituting the odd speed gear train group G1 and the even speed gear train group G2 in the gear chamber 2b. It is sufficient that the clutch gears 20 and 30 and the first and second clutches 21 and 31 and the input gear 7a at the front end of the input shaft 7 are accommodated, and the lower end of the clutch chamber 2c is shown in FIG. As can be seen from the arrangement of the front end edge 4b of the main housing 4, the main housing 4 is arranged immediately below the input gear 7a and the second clutch gear 31. On the other hand, in the front view, the main housing 4 is located below the lower end of the front end edge 4b. 4, a lower front end wall 4p is extended, and the lower front end wall 4p defines a front end wall of an oil reservoir below the gear chamber 2b.

  Therefore, even if the oil in the oil reservoir in the gear chamber 2b communicates with the clutch chamber 2c via the bearings in the bearing wall 4c and the oil reservoir in the clutch chamber 2c is formed, the oil level FL Is not much different from the height of the oil level FL of the oil reservoir in the gear chamber 2b, and is also below the input gear 7a and the second clutch gear 30 (and the second clutch 31), as shown in FIG. Agitation resistance to the gear and clutch accommodated in the clutch chamber 2c does not become a problem.

  As shown in FIGS. 5 and 7, the electromagnetic proportional valves 71 and 72 for supplying hydraulic oil to the first and second clutches 21 and 31 are configured at a high position of the main housing 4 as described above. The lid 5 is attached to the front edge 4b. Therefore, the electromagnetic proportional valves 71 and 72 are arranged at a high position, which is a preferable arrangement for ensuring the waterproofness of each solenoid coil.

  Further, the electromagnetic proportional valves 71 and 72 have solenoid coils placed on the outer side in the left-right direction (this embodiment) on a pair of upper and lower bosses formed in a vertical arrangement on the left and right side ends (the left end in this embodiment) of the front end of the lid 5. In the example, it is mounted in a state protruding left). In the present embodiment, as described above, the first clutch 21 disposed above the input gear 7a is positioned higher than the second clutch 31 at substantially the same height as the input gear 7a. The electromagnetic proportional valve 72 for the second clutch 31 is disposed below, and the electromagnetic proportional valve 71 for the first clutch 21 is disposed above.

  In this way, the electromagnetic proportional valves 71 and 72 protrude from the solenoid coil in the left-right direction and are attached to the lid body 5 in an easily detachable state, so that the lid body 5 is attached to the main housing 4. Even if it remains as it is, it is possible to easily access the electromagnetic proportional valves 71 and 72 mounted on the lid 5 by simply rotating the seat 108 and the seat mounting plate 103a as described above, and attach / detach to the lid 5 for maintenance. Can also be done easily.

  Further, as shown in FIG. 5 and FIG. 9 and the like, the first and second clutches 21 are attached to the lid 5 at a position further above the electromagnetic proportional valve 71 among the electromagnetic proportional valves 71 and 72. A relief valve 70 is provided for regulating the working hydraulic pressure to 31 to a predetermined pressure.

  As can be seen in FIGS. 5 and 8, the drum shaft 16 and the fork shafts 161 and 162 arranged in parallel adjacent to the drum shaft 16 extend horizontally in the front-rear direction in the upper portion of the gear chamber 2b. It is installed. Three forks (not shown) are supported on the fork shaft 161 so as to be slidable in the axial direction, and are respectively fitted to the shifters 28, 36, and 45. A fork (not shown) is supported on the fork shaft 162 so as to be slidable in the axial direction, and is fitted to the shifter 29.

  On the other hand, a drum (not shown) having four shift grooves is fixed to the drum shaft 16, and operation pins of the four forks are fitted into the shift grooves, respectively. The fork is moved in the axial direction of the fork shafts 161 and 162 by the operation pins fitted in the respective shift grooves moving in the axial direction according to the shape of the respective shift grooves in accordance with the rotation of the fork shaft. It has become.

  Further, a potentiometer 17b for detecting the rotational position of the drum shaft 16 is provided, and a harness 17c extending from the potentiometer 17b is connected to a controller (not shown) provided in the transport vehicle 100.

  Since these electrical components 17a, 17b, and 17c are disposed on the upper portion of the main housing 4, the electrical components 17a, 17b, and 17c are excellent in waterproofness and are easy to connect to and maintain the controller.

  The actuator 17 and its associated electrical components 17a, 17b, and 17c are concentratedly attached to the front end surface of the main housing 4 so that when the seat 108 and the seat mounting plate 103a are rotated as described above, access and These are arranged in a place where they can be easily attached and detached.

  In addition, the upper right portion of the lid 5 is formed in an inclined shape by the oblique arrangement in the vertical and horizontal directions of the first clutch 21 and the second clutch 31 as described above, whereby the upper front end surface of the main housing 4 Such an actuator 17 and related electric parts are attached in a compact and concentrated manner along the lid 5.

  A starter motor Ec for starting the engine E is attached to the front end surface of the upper left portion of the main housing 4. This portion is on the right side of the right end of the lid 5 attached to the front end portion of the main housing 4, and the lower portion of the gear chamber 2b configured to secure an oil reservoir below the lower end of the clutch chamber 2c as will be described later. In this way, the starter motor Ec is used as a part where the starter motor Ec is disposed by using the dead space above the left and right extension parts generated by providing the left extension part. Since it is arranged on the side so as to protrude forward, it is easy to perform maintenance work, and it is an arrangement that ensures compactness.

  In the dual clutch transmission 1, the hydraulic pump unit 50 is accommodated in the transmission case 2, and the oil discharged from the hydraulic pump unit 50 is the hydraulic clutch unit 60 via the electromagnetic proportional valves 71 and 72. The hydraulic oil is supplied to the first and second clutches 21 and 31, and a part of the discharged oil is used as lubricating oil for the clutches and gears in the gear chamber 2b and the clutch chamber 2c and various bearings. Supply.

  As a result, even if the gears and clutches in the gear chamber 2b and the clutch chamber 2c are arranged above the oil level FL of the oil sump as described above, the gears and clutches are sufficiently lubricated. , Ensuring durability.

  With respect to the hydraulic oil / lubricant supply system using the oil discharged from the hydraulic pump unit 50, first, the flow of the oil will be described with reference to FIG.

  The hydraulic pump unit 50 includes a first hydraulic pump 50a and a second hydraulic pump 50b that are driven in tandem with the output shaft Ea of the engine E. Here, the first hydraulic pump 50a supplies pressure oil as hydraulic oil for the first and second clutches 21 and 31 regardless of the rotational speed of the engine E. The second hydraulic pump 50b Only when the rotational speed of the engine E increases, the discharged oil is added to the discharged oil from the first hydraulic pump 50a and supplied as the working oil for the first and second clutches 21 and 31. .

  That is, the first and second hydraulic pumps 50 a and 50 b of the hydraulic pump unit 50 are both driven by the engine E and suck oil from the oil reservoir in the gear chamber 2 b of the transmission case 2 through the filter 49. .

  As long as the engine E is driven, the first hydraulic pump 50a always discharges oil, and the oil is electromagnetic for the first clutch 21 in the oil passage (the hydraulic oil supply oil passage 5b described later) in the lid 5. It is distributed to the proportional valve 71 and the electromagnetic proportional valve 72 for the second clutch, and the hydraulic oil chamber of the first clutch 21 or the hydraulic oil chamber of the second clutch 31 according to the solenoid control of the electromagnetic proportional valves 71 and 72. The first clutch 21 or the second clutch 31 is engaged by supplying oil to the hydraulic oil chamber, and the first clutch is released by discharging oil from the hydraulic oil chamber. 21 or the second clutch 31 is separated.

  The second hydraulic pump 50b always discharges oil as long as the engine E is driven, and the discharged oil is discharged from the first hydraulic pump 50a via the check valve 56 only when the unload valve 55 is closed. It merges with the discharged oil and flows toward the electromagnetic proportional valves 71 and 72. That is, when the unload valve 55 is closed, a large volume of discharged oil from the first and second hydraulic pumps 50a and 50b is supplied as hydraulic oil for the first and second clutches 21 and 31. On the other hand, by opening the unload valve 55, the discharge oil of the second hydraulic pump 50b is returned to the primary side (upstream side) of the first and second hydraulic pumps 50a and 50b.

  In the relief valve 70 described above, whether the discharge oil from the hydraulic pump unit 50 is from only the first hydraulic pump 50a or whether the discharge oil from the first hydraulic pump 50a and the second hydraulic pump 50b is merged. Regardless, the hydraulic pressure supplied to the first and second clutches 21 and 31 is kept constant.

  The unload valve 55 is an electromagnetic switching valve, and is an open / close valve that is automatically switched between a valve open state and a valve closed state by a controller based on detection of the rotational speed of the engine E. The controller (not shown) closes the unload valve 55 until the detected engine speed ranges from the idle speed to a predetermined speed, and outputs from both the first and second hydraulic pumps 50a and 50b. In the region where the discharged oil is merged and the engine speed exceeds the predetermined speed and reaches the highest speed, the unload valve 55 is opened, and substantially only the amount of discharged oil from the first hydraulic pump 50a, The hydraulic oil is supplied to the first and second clutches 21 and 31.

  As described above, the hydraulic pump unit 50 includes the two fixed displacement hydraulic pumps 50a and 50b, and combines the discharged oil from both of them to supply the first and second clutches 21 and 31, or The pump capacity is switched depending on whether the discharge oil of only the first hydraulic pump 51a is supplied.

  As another form in which the pump capacity can be switched in this way, for example, one variable displacement type hydraulic pump is provided, such as an axial piston type hydraulic pump having a movable swash plate, and the tilt angle of the movable swash plate is changed. For example, a structure in which the volume is changed can be considered. In this case, it is conceivable that the volume adjusting unit such as the movable swash plate is controlled by an electric actuator, and the electric actuator is controlled by a command signal transmitted from the controller based on detection of the engine speed.

  The dual clutch type speed change system that realizes the hydraulic oil supply system to the first and second clutches 21 and 31 by the oil discharged from the hydraulic pump unit 50 as described above and the lubricating oil supply system to each part in the gear chamber 2b and the clutch chamber 2c. A specific structure of the apparatus 1 will be described with reference to FIGS.

  As described above, the oil reservoir is provided in the lower part of the gear chamber 2b with the lower front end wall 4p of the main housing 4 as the front end, and is shown in FIGS. 8 and 12 at a lower position below the oil level FL. Thus, the cylindrical filter 49 is arrange | positioned in the state immersed in the oil sump.

  As shown in FIGS. 5, 6, and 8, the left and right sides of the main housing 4 (in this embodiment, the right side portion where the output shaft 12 and the like are provided are provided so that the filter 49 for maintenance can be easily removed. A filter removal hole is provided on the left side opposite to the above and is closed by a detachable cap 49a.

  In the gear chamber 2 b, an oil passage pipe member 51 that is bent in an L shape in front view is extended from the inner end portion of the filter 49, and the upper end thereof is connected to the bottom portion of the hydraulic pump unit 50.

  The hydraulic pump unit 50 has a housing formed by joining a cover plate 52, a pump block 53, and an oil passage block 54. The pump block 53 includes a gear pump as two first and second hydraulic pumps 50a and 50b and A check valve 56 is housed, and an unload switching valve 55 is housed in the oil passage block 54.

  The front surface of the cover plate 52 and the rear surface of the pump block 53 are brought into contact with each other, the front surface of the pump block 53 is brought into contact with the rear surface of the oil passage block 54, and the cover plate 52, the pump block 53, and the oil passage block 54 are connected by bolts 57. The housing is configured by fastening together.

  Further, the front surface of the oil passage block 54 is in contact with the wall portion of the main housing 4, and the front end portion of the bolt 57 passing through the cover plate 52, the pump block 53, and the oil passage block 54 is connected to the wall portion of the main housing 4. The hydraulic pump unit 50 is fixed to the main housing 4 by being screwed into the main housing 4.

  As shown in FIG. 12, the mounting position of the hydraulic pump unit 50 in the main housing 4 extends from the portion corresponding to the bottom of the clutch chamber 2c to the upper portion of the lower front end wall 4p below it. The position in the left-right direction is a portion closer to the left end of the main housing 4. The unload valve 55 is mounted from the outside of the main housing 4 (mission case 2) into the oil passage block 54 through a front and rear through hole 4h formed in the upper part of the lower front end wall 4p of the main housing 4. Has been.

  Each of the first hydraulic pumps 50a is a gear pump formed by combining an inner rotor and an outer roller surrounding the inner rotor. The pump drive shaft 14 passes through the cover plate 52, and its front end is disposed in the pump block 53. The first and second hydraulic pumps 50a and 50b are connected to the front end of the pump drive shaft 14. Yes.

  An oil passage 51 a is formed in the oil passage pipe member 51 in a penetrating manner from the lower end connected to the filter 49 to the lower end connected to the hydraulic pump unit 50. The upper end of the oil passage pipe member 51 is connected to the bottom end of the joint between the cover plate 52 and the pump block 53.

  A suction oil passage 52a is formed along the front surface of the cover plate 51 so as to extend vertically upward from the lower end to the middle of the top and bottom. The upper end of the suction oil passage 52 a communicates with the suction port of the first hydraulic pump 50 a along the rear surface of the pump block 53.

  Further, a discharge oil passage 52b is formed in a vertically extending shape from a position slightly above the suction oil passage 52a on the front surface of the cover plate 52, and a lower end portion of the discharge oil passage 52b is discharged from the first hydraulic pump 50a. It communicates with the port.

  A hydraulic oil supply oil passage 53b in the front-rear horizontal direction is formed in the front and rear horizontal direction in a portion of the pump block 53 above the first and second hydraulic pumps 50a and 50b. It is connected to the upper end part of the discharge oil path 52b formed along the front surface.

  Corresponding to the hydraulic oil supply oil passage 53b in the pump block 53, a hydraulic oil supply oil passage 54d in the front-rear and horizontal directions is also formed in the front and rear in the upper part of the oil passage block 54, and the hydraulic oil supply oil passage 54d. The rear end is connected to the front end of the hydraulic oil supply oil passage 53 b in the pump block 53.

  Further, as described above, the hydraulic oil supply oil passage 4d in the front-rear horizontal direction is formed in the wall portion of the main housing 4 corresponding to the bottom of the clutch chamber 2c, and the rear end of the hydraulic oil supply oil passage 4d The hydraulic oil supply oil passage 54d in the passage block 54 is connected to the front end.

  In the pump block 53, a secondary suction oil passage 53a is formed so as to communicate the suction port of the first hydraulic pump 50a and the suction port of the second hydraulic pump 50b in front thereof.

  Part of the oil that has flowed from the oil passage 51a of the oil passage pipe member 51 into the suction port of the first hydraulic pump 50a through the suction oil passage 52a of the cover plate 52 is driven by the first hydraulic pump 50a. The pressure is fed to the discharge port of the first hydraulic pump 50a, and the others flow into the suction port of the second hydraulic pump 50b via the secondary suction oil passage 53a.

  A check valve 56 is provided in the pump block 53 and the oil passage block 54 so as to penetrate the joint surface between the pump block 53 and the oil passage block 54, and a rear end portion thereof is formed in the pump block 53. The hydraulic oil supply oil passage 53b is connected to the front end portion of the oil passage block 54, which is connected to the communication oil passage 54c. The oil from the communication oil passage 54c to the hydraulic oil supply oil passage 53b Only the flow is allowed.

  The communication oil passage 54 c communicates with an inlet port of an unload valve 55 mounted in the oil passage block 54. Further, in the oil passage block 54, a return oil passage 54a that connects the suction port of the second hydraulic pump 50b and the outlet port of the unload valve 55, and a discharge port and a communication oil passage 54c of the second hydraulic pump 50b. A discharge oil passage 54b is formed.

  The second hydraulic pump 50b is driven by the pump drive shaft 14 in synchronization with the first hydraulic pump 50a, and the oil taken into the suction port via the secondary suction oil passage 53a is discharged from the discharge port to the discharge oil passage 54b. To the connecting oil passage 54c.

  At this time, if the unload valve 55 is closed, the oil flowing into the connecting oil passage 54c from the discharge oil passage 54b opens the check valve 56, and the hydraulic oil supply oil passage 53b in the oil passage block 53 is opened. And flows into the hydraulic oil supply oil passage 54d and the hydraulic oil supply oil passage 4d through the discharge oil passage 53b, where the oil is discharged from the first hydraulic pump 50a through the discharge oil passage 52b. .

  On the other hand, if the unload valve 55 is open, the oil that has flowed into the connecting oil passage 54c from the discharge oil passage 54b passes through the return oil passage 54a from the unload valve 55 to the suction port of the second hydraulic pump 50b. Returned to the suction port of the first hydraulic pump 50a via the secondary suction oil passage 53a.

  A hydraulic oil supply oil passage 5b is bored from the portion of the lid 5 that becomes the bottom wall of the clutch chamber 2c to the portion that becomes the front wall of the clutch chamber 2c. The lower end portion of the hydraulic oil supply oil passage 5 b is an oil hole in the front and rear horizontal direction, and the rear end thereof is connected to the front end of the hydraulic oil supply oil passage 4 d in the main housing 4.

  As shown in FIG. 12, a horizontal oil hole is formed behind the relief valve 70 provided in the upper left part of the lid 5, and is connected to the hydraulic oil supply oil passage 4 d of the main housing 4. From the front end of the oil hole to the rear end of the oil hole in the front-rear direction connected to the relief valve 70, an oil hole is vertically drilled along the left end of the lid 5 as shown in FIG. . The vertical oil hole, the oil hole extending in the rear horizontal direction from the lower end of the vertical oil hole to the hydraulic oil supply oil passage 4d of the main housing 4, and the relief valve 70 from the lower end of the vertical oil hole. A hydraulic oil supply oil passage 5b in the lid 5 is configured by an oil hole connected to the front in the horizontal direction.

  Further, as shown in FIGS. 7 and 12, the second clutch shaft 9 located on the right side of the vertical oil hole of the hydraulic oil supply oil passage 5 b in the lid 5 has a ring shape described later. A horizontal oil hole is drilled up to the groove 9a, and this oil hole serves as a second clutch hydraulic oil supply oil path 5d, and at a position above it, the vertical of the hydraulic oil supply oil path 5b. Left and right oil holes are drilled from the upper and lower middle portions of the oil holes to the later-described annular groove 8a of the first clutch shaft 8 positioned on the right side of the oil holes. 5c.

  Of the upper and lower electromagnetic proportional valves 71 and 72 mounted from the left end of the lid body 5, the lower electromagnetic proportional valve 72 is connected to the vertical oil hole of the hydraulic oil supply oil passage 5b. The supply oil passage 5d is inserted into the lid 5 up to the starting point. Here, the electromagnetic proportional valve 72 communicates the suction port with the vertical oil hole of the hydraulic oil supply oil passage 5b, and the discharge port is the second. It communicates with the clutch hydraulic oil supply oil passage 5d.

  Further, the upper electromagnetic proportional valve 71 is fitted in the lid 5 up to the starting point of the first clutch hydraulic oil supply oil passage 5c connected to the vertical oil hole of the hydraulic oil supply oil passage 5b. The electromagnetic proportional valve 71 communicates the suction port with the vertical oil hole of the hydraulic oil supply oil passage 5b and communicates the discharge port with the hydraulic oil supply oil passage 5c for the first clutch.

  As shown in FIG. 9, the lid 5 is formed with a shaft hole 5f into which the front end portion of the first clutch shaft 8 is fitted, and the shaft hole into which the front end portion of the second clutch shaft 9 is fitted. 5h is formed. An annular groove 8a is fitted on the outer peripheral surface of the first clutch shaft 8 which is fitted to the inner peripheral surface of the shaft hole 5f so as to be relatively slidable and rotatable. An annular groove 9 a is formed on the outer peripheral surface of the combined second clutch shaft 9.

  As can be seen in FIG. 7, the terminal end (right end) of the first clutch hydraulic oil supply oil passage 5c opens at the inner peripheral surface of the shaft hole 5f, and the annular groove of the first clutch shaft 8 in the shaft hole 5f. It communicates with 8a. On the other hand, the terminal end (right end) of the second clutch hydraulic oil supply oil passage 5d opens at the inner peripheral surface of the shaft hole 5h and communicates with the annular groove 9a of the second clutch shaft 9 in the shaft hole 5h. .

  As shown in FIG. 9, a hydraulic fluid passage 8 b in the axial direction is formed in the first clutch shaft 8, and a hydraulic fluid passage 9 b in the axial direction is formed in the second clutch shaft 9. It is installed. One end (the front end in the present embodiment) of each hydraulic oil passage 8b and 9b communicates with each annular groove 8a and 9a through a radial oil hole, and the other end (the main end of each hydraulic oil passage 8b and 9b) In the embodiment, the rear end) is opened at the outer peripheral surface of each clutch shaft 8 and 9 via other radial oil holes, and each of the first and second clutches 21 and 31 as the hydraulic clutch unit 60 is provided. It communicates with the hydraulic oil chamber. The configuration of the hydraulic clutch unit 60 as each of the first and second clutches 21 and 31 will be described in detail later.

  As can be seen from FIGS. 7 and 9, in the lid 5, a straight oil hole is formed obliquely to the lower right of the relief valve 70 in order to guide the oil discharged from the relief valve 70 as lubricating oil. The hole is a lubricating oil passage 5e. The lubricating oil passage 5e is connected to the front ends of the shaft holes 5f and 5h into which the front end portions of the clutch shafts 8 and 9 are fitted.

  In the first clutch shaft 8, a lubricating oil passage 8 c in the axial direction is formed in parallel with the hydraulic oil passage 8 b, and the front end thereof opens at the front end of the first clutch shaft 8. A gap is provided between the front end of the shaft hole 5f and the front end of the first clutch shaft 8, and this gap is used as an oil transfer chamber 5f1. Thus, the oil discharged from the relief valve 70 can flow into the lubricating oil passage 8c from the lubricating oil passage 5e through the oil transfer chamber 5f1.

  On the other hand, a lubricating oil passage 9c is formed in the second clutch shaft 9 in the axial direction parallel to the hydraulic oil passage 9b, and its front end opens at the front end of the second clutch shaft 9. Yes. A clearance is provided between the front end of the shaft hole 5h and the front end of the second clutch shaft 9, and this clearance is used as the oil transfer chamber 5h1. Thus, the oil discharged from the relief valve 70 can flow into the lubricating oil passage 9c from the lubricating oil passage 5e through the oil transfer chamber 5h1.

  As shown in FIG. 9, in the clutch chamber 2c, oil holes are branched in the radial direction from the lubricating oil passages 8c and 9c in the clutch shafts 8 and 9, and the oil holes are divided into the clutch shafts 8 and 9c. 9 is opened to the outer peripheral surface of the first and second clutches 21 and 31 attached to this portion, and oil for suppressing centrifugal hydraulic pressure to the centrifugal hydraulic pressure canceling chamber 60b, which will be described later, and clutch plates 62 and 63 As the lubricating oil, the oil discharged from the relief valve 70 is supplied.

  Further, the lubricating oil passages 8c and 9c are extended to the rear ends of the first clutch shaft 8 and the second clutch shaft 9 that are pivotally supported by the bearing wall 3b at the rear end of the gear chamber 2b. That is, the clutch shafts 8 and 9 are formed to penetrate in the front-rear direction. Therefore, the oil that has passed through the lubricating oil passages 8c and 9c flows out from the rear ends of the clutch shafts 8 and 9, lubricates the bearings that support the rear ends of the clutch shafts 8 and 9, and the gear chamber 2b. It is returned to the oil sump inside.

  Further, as shown in FIG. 9, the variable speed driven shaft 10 and the counter shaft 11 are also supported by the bearing wall 3b from the front ends of the shafts 10 and 11 supported by the bearing wall 4c. Lubricating oil passages 10a and 11a in the axial direction are drilled in the front-rear direction to the rear ends of the shafts 10 and 11 that are located.

  The main housing 4 is provided with an oil hole in the front-rear horizontal direction from a vertical surface facing the front end of the speed change driven shaft 10 in the bearing wall 4 c to a front end surface of the main housing 4 that is in contact with the lid 5. This is the lubricating oil passage 4e. On the other hand, an oil hole in the front-rear horizontal direction is drilled from the vertical surface of the main housing 4 facing the front end of the counter shaft 11 on the bearing wall 4c to the front end surface of the main housing 4 that is in contact with the lid 5; This is the lubricating oil passage 4f.

  In the lid 5, as shown in FIG. 7 and FIG. 9, a connecting portion of the lubricating oil passage 5 e that is a slanted straight oil hole in front view and the oil transfer chamber 5 f 1 (the front end of the shaft hole 5 f) , An oil hole is formed in an upward direction (specifically, an upper right oblique direction) from a portion between the oil passage chamber 5h1 (the front end of the shaft hole 5h) and a horizontal position behind the upper end of the oil hole. An oil hole is drilled and the rear end thereof is connected to the front end of the lubricating oil passage 4 e of the main housing 4. The oil holes in these lids 5 constitute a lubricating oil passage 5g that branches from a middle portion of the lubricating oil passage 5e and guides the oil to the lubricating oil passage 4e of the main housing 4.

  The oil discharged from the relief valve 70 is introduced into the lubricating oil passage 10a in the transmission driven shaft 10 via the lubricating oil passage 5g of the lid 5 and the lubricating oil passage 4e of the main housing 4, and eventually the transmission driven. It flows out from the rear end of the shaft 10 and is returned to the oil sump in the gear chamber 2b.

  Further, the end portion of the lubricating oil passage 5e is a connecting portion to the shaft hole 5h into which the front end portion of the second clutch shaft 9 is fitted, but it faces upward from the end portion of the lubricating oil passage 5e (in detail, An oil hole (in the upper right oblique direction) is drilled, a horizontal oil hole is drilled behind the upper end of the oil hole, and the rear end is connected to the front end of the lubricating oil passage 4 f of the main housing 4. These oil holes in the lid 5c constitute a lubricating oil passage 5i that branches from the end portion of the lubricating oil passage 5e and guides the oil to the lubricating oil passage 4f of the main housing 4.

  The oil discharged from the relief valve 70 is introduced into the lubricating oil passage 11a in the counter shaft 11 through the lubricating oil passage 5i of the lid 5 and the lubricating oil passage 4f of the main housing 4, and eventually the counter shaft 11 It flows out from the rear end and is returned to the oil sump in the gear chamber 2b.

  In the gear chamber 2 b, the inner peripheral surface of the fifth speed drive gear 26 is provided on the outer peripheral surface of the first clutch shaft 8, and the first speed driven gear 23 and the third speed driven gear 25 are provided on the outer peripheral surface of the transmission driven shaft 10. , The inner peripheral surface of each of the second speed driven gear 33 and the fourth speed driven gear 35 and the inner peripheral surface of the reverse driven gear 44 on the outer peripheral surface of the counter shaft 11 are relatively rotated via a bush. Wearing freely. For lubrication of the bush, a radial oil hole branches off from the lubricating oil path 8 c in the first clutch shaft 8, the lubricating oil path 10 a in the transmission driven shaft 10, and the lubricating oil path 11 a in the counter shaft 11. The opening is made at the outer peripheral surface of each shaft, and faces each bush.

  In this way, the oil discharged from the relief valve 70 for regulating the hydraulic pressure applied to the first and second clutches 21 and 31 attached to the lid 5 is supplied to the first and second clutches 21 and 31 in the clutch chamber 2c. In the clutch chamber 2b, each gear loosely fitted on the shaft is supplied as lubricating oil. As described above, most of the gears and clutches in the gear chamber 2b and the clutch chamber 2c are oil in the oil reservoir. Even if the structure is arranged higher than the surface FL, the lubricating oil is surely supplied to these members.

  In the above description, the clutch hydraulic oil and lubricating oil supply structure is described on the assumption that the hydraulic pump unit 50 is disposed in the gear chamber 2b as shown in FIG. The hydraulic pump unit may be arranged in the clutch chamber 2c.

  FIG. 13 shows a structure in which a hydraulic pump unit 50A of another embodiment is arranged in the clutch chamber 2c. The embodiment of FIG. 13 will be described.

  In the above embodiment, the lower end of the clutch chamber 2c is disposed immediately below the input gear 7a. In this embodiment, the clutch chamber 2c is further moved downward from this position to a position corresponding to the lower end of the gear chamber 2b. Has been extended. That is, the opening defined by the front end edge 4b of the main housing 4 is expanded downward, and the front end edge 4b is formed over substantially the entire circumference of the front end of the main housing 4, and the flange edge 5a of the lid 5 is correspondingly formed. Is also formed extending downward.

  Thus, the lower expansion chamber 2d is formed below the position corresponding to the lower end of the clutch chamber 2c of the above-described embodiment, and the portion of the main housing 4 which is the lower front end wall 4p in the previous embodiment is replaced with the gear chamber 2b. A lower partition 4p1 that divides the lower portion and the lower extension chamber 2d of the clutch chamber 2c is used, and a lower extension portion 5p of the lid 5 is a front wall of the lower extension chamber 2d.

  An oil reservoir is provided in the lower extension chamber 2d, and the filter 49 is attached to the wall portion of the main housing 4 corresponding to the right wall portion of the lower extension chamber 2d so as to be immersed in the oil reservoir. A hole similar to the previously formed hole is formed, and the filter 49 is disposed in the lower part of the lower expansion chamber 2d by being inserted into the hole.

  A through hole 4p2 that connects the rear gear chamber 2b and the front lower expansion chamber 2d is formed in the lower part of the lower partition 4p1, and an oil sump in the gear chamber 2b is formed through the through hole 4p2. The oil can flow between the oil reservoir in the lower expansion chamber 2c of the clutch chamber 2c.

  In the upper part of the lower extension chamber 2d, the hydraulic pump unit 50A is arranged so as to be sandwiched between the lower partition 4p1 of the main housing 4 and the lower extension part 5p of the lid 5. As the housing of the hydraulic pump unit 50A, only the pump block 53 and the oil passage block 54 are used, and the rear surface of the pump block 53 is brought into contact with the front end surface of the upper partition 4p1 of the main housing 4 so that the oil passage block 54 The front surface is in contact with the upper inner surface (rear surface) of the lower extension portion 5p of the lid 5.

  The bolt 57 is passed from the front through the oil passage block 54 and the pump block 53, and the rear end portion is screwed into the lower partition wall 4p1 of the main housing 4, whereby the pump block 53 and the oil passage which are the housing of the oil passage pump unit 50A The block 54 is fixed to the main housing 4.

  The bolt 57 may be inserted from the rear into the pump block 53 and the oil passage block 54 and screwed into the lid 5 to fasten the housing of the hydraulic pump unit 50A to the lid 5 or the main It is good also as what fastens to both the housing 4 and the cover body 5. FIG.

  The arrangement configuration of the first and second hydraulic pumps 50a and 50b and the oil passages 53a and 53b in the pump block 53, the arrangement configuration of the unload valve 55 and the oil passages 54a, 54b, 54c and 54d in the oil passage block 54, and the pump The arrangement configuration of the check valve 56 in the block 53 and the oil passage block 54 is the same as that of the hydraulic pump unit 50.

  However, the unload valve 53 in the oil passage block 54 is arranged not in front of the oil passage block 54 but in front of the lower front end wall 4p of the main housing 4 and in an upper portion of the lower extension portion 5p of the lid 5. is there. Correspondingly, a front and rear through-hole 5k is provided in the upper part of the lower extension portion 5p of the lid 5, and the unload valve 53 is inserted from the front end of the lower extension portion 5p of the lid 5 through the hole 5k. It is supposed to be. Thereby, even if it is the structure which additionally formed the downward expansion chamber 2d in the clutch chamber 2c, the unload valve 55 can be extracted ahead of the transmission case 2, and the maintainability is ensured.

  Further, since the oil passage block 54 and the lid 5 are in direct contact with each other, the front end of the hydraulic oil supply oil passage 54d in the oil passage block 54 is the lower end of the hydraulic oil supply oil passage 5b in the lid 5. It is directly connected to the rear end of the oil hole in the front-rear direction.

  The upper end portion of the oil passage pipe member 51 extending from the filter 49 is connected to the bottom end portion of the joint of the pump block 53 and the oil passage block 54. Correspondingly, a suction oil passage 54a1 extending downward from the return oil passage 54a formed to communicate with the suction port of the second hydraulic pump 50b is formed in a groove shape along the rear surface of the oil passage block 54. The lower end of the suction oil passage 54 a 1 is connected to the upper end of the oil passage 51 a in the oil passage pipe member 51.

  On the other hand, instead of the cover plate 52, a vertical discharge oil passage 4i is formed in a groove shape along the front surface of the lower partition 4p1 of the main housing 4 that contacts the rear surface of the oil passage block 53, and the lower end thereof is One hydraulic pump 50 a communicates with the discharge port, and its upper end is connected to the rear end of the discharge oil passage 53 b in the oil passage block 53. The pump drive shaft 14 is pivotally supported by a lower partition 4p1 of the main housing 4 via a bearing, and a front end portion thereof projects into the pump housing 53.

  The control of the discharge amount by the hydraulic clutch hydraulic oil supply unit 50 or 50A and the effect thereof as described above will be described based on the correlation diagram of the discharge oil amount Q with respect to the rotational speed N of the engine E in FIG.

  The controller (not shown) closes the unload valve 55 when the rotational speed N of the engine E detected by the rotational speed sensor or the like is less than a predetermined value N2, and controls the first and second hydraulic pumps 50a and 50b. The oil discharged from both sides is supplied to the hydraulic oil supply oil passage 5 b in the lid 5. The discharged oil amount Q increases as the engine speed N increases, and is required for the operation of the first clutch 21 or the second clutch 31 when the engine speed N reaches the idling speed N1. Is set so as to reach only the amount Q1.

  Therefore, for example, if the shifter 28 is set to the forward first speed position, the shifter 45 is set to the reverse position, and the first clutch 21 is engaged during idling rotation of the engine E, the transport vehicle 100 can be smoothly moved to the first speed. The vehicle 100 can be started forward, and if the second clutch 31 is engaged with the idling speed, the transport vehicle 100 can be smoothly started backward.

  The oil supplied to the hydraulic oil supply oil passage 5b from the hydraulic pump unit 50 (50A) after the hydraulic oil chamber 60a in the clutch 21 or 31 on the engaging side is filled with the hydraulic oil of the oil amount Q1. Most of the oil is released to the lubricating oil passage 5e via the relief valve 70.

  As the engine speed N increases from the idling speed N1, the discharge oil quantity Q increases, and the hydraulic oil quantity Q1 required to engage one of the first clutch 21 and the second clutch 31 is reduced. The oil discharged beyond the pressure is released from the relief valve 70 to the lubricating oil passage 5e, and is supplied as lubricating oil to the parts that require the lubricating oil in the clutch chamber 2c and the gear chamber 2b.

  Eventually, the discharged oil amount Q reaches the upper limit value Q3 (hereinafter, simply referred to as “upper limit value Q3”) of the total oil amount required for the dual clutch transmission 2 as a whole. This is the sum of the clutch hydraulic oil amount Q1 and the upper limit value Q2 of the lubricating oil amount required for the dual clutch transmission 2 as a whole (hereinafter referred to as “lubricating oil upper limit amount Q2”).

  The engine speed N detected at this time has reached a predetermined value N2, and the controller opens the unload valve 55 that has been closed until then based on the detection of the engine speed N of the predetermined value N2. To do. As a result, oil is discharged from the hydraulic pump unit 50 (50A) only by the first hydraulic pump 50a, and the discharge oil amount Q is halved from the upper limit value Q3 here, but the hydraulic oil amount Q1 is ensured. ing.

  The amount Q of oil discharged only from the first hydraulic pump 50a increases as the engine speed N increases, and reaches the upper limit Q3 when the engine speed N reaches the maximum speed Nmax. It is said.

  Temporarily, the unload valve 55 is kept closed until the engine speed N reaches the maximum speed Nmax, and the discharge oil from both the first hydraulic pump 50a and the second hydraulic pump 50b is supplied to the hydraulic oil supply oil passage 5b. In the region of the engine speed N from the predetermined value N2 to the maximum speed Nmax, the amount of oil exceeding the upper limit value Q3 increases to the hydraulic oil supply oil passage 5b as the engine speed N increases. Continue to be supplied. At the stage where the engine speed N reaches the maximum speed Nmax, the discharge oil amount Q that is approximately twice the upper limit value Q3 is supplied.

  In the region of the engine speed N from the predetermined value N2 to the maximum speed Nmax, the relief valve 70 continues to release the amount of oil exceeding the lubricating oil upper limit amount Q2 to the lubricating oil passage 5e and is used as lubricating oil. Without being returned to the oil reservoir in the gear chamber 2b (and the clutch chamber 2c), during which the power of the engine E is wasted for driving the hydraulic pumps 50a and 50b.

  Therefore, as described above, when the engine speed N reaches the predetermined value N2, the unload valve 55 is opened and the second hydraulic pump 50b is unloaded (no-load operation). In the region of the engine speed N up to the speed Nmax, the energy consumption SE for driving the second hydraulic pump 50b, which is represented as a shaded portion in FIG. 14, is omitted, and the fuel efficiency of the transport vehicle 100 can be improved. it can.

  In the present embodiment, the first hydraulic pump 50a and the first hydraulic pump 50b have the same displacement volume, but are not limited thereto.

  Next, the structure of the hydraulic clutch unit 60 provided as the first and second clutches 21 and 31 will be described with reference to FIGS. 10 discloses a hydraulic clutch unit 60 as the first clutch 21, and the configuration of the hydraulic clutch unit 60 as the second clutch 31 will be described below. The configuration is the same as that of 60, and the description thereof is omitted.

  The hydraulic clutch unit 60 includes a clutch case 61 fixed on the clutch shaft 8, a clutch gear 20 loosely fitted on the clutch shaft 8, and the clutch case 61 interposed between the clutch case 61 and the clutch gear 20. The clutch plates 62 and 63, the receiving plate 64, the retaining ring 65, the piston 66, the spring 67, the centrifugal hydraulic canceller (hereinafter simply referred to as “canceller”) 68, and the lubricating oil guide plate 69 are combined.

  The clutch case 61 has the inner peripheral surface of the central boss portion 61a fixed to the outer peripheral surface of the clutch shaft 8, and a vertical plate portion 61b is extended from the front end portion of the central boss portion 61a in a centrifugal shape. A circumferential portion 61c extends from the outer peripheral edge of 61b to surround the central boss portion 61a.

  A bearing is interposed between the inner peripheral surface of the clutch gear 20 disposed behind the clutch case 61 and the outer peripheral surface of the clutch shaft 8, and the clutch gear 20 is loosely fitted to the clutch shaft 8. A cylindrical portion 20 a extends forward from the clutch gear 20, and this is defined as a space between the central boss portion 61 a of the clutch case 61 and the surrounding circumferential portion 61 c (hereinafter, this space is referred to as “clutch case 61. In the interior space).

  The outer peripheral portion of the cylindrical portion 20a of the clutch gear 20 is engaged with the inner peripheral edges of a plurality of steel plates 62 arranged in the front and rear directions so as not to be relatively rotatable and slidable in the axial direction (front and rear direction). An outer peripheral edge of a plurality of friction plates 63 arranged in the front-rear direction is engaged with the inner peripheral part of the peripheral part 61 c of 61 so as not to be relatively rotatable and to be slidable in the axial direction (front-rear direction). The steel plates 62 and the friction plates 63 are alternately arranged in the front-rear direction as clutch plates.

  Of these clutch plates 62 and 63, a receiving plate 64 is arranged immediately after the clutch plate arranged at the rearmost end, and is engaged with the peripheral portion 61c of the clutch case 61 so as not to be relatively rotatable. Is locked by a retaining ring 65 so as not to move in the axial direction.

  The piston 66 is centered in the front half of the inner space of the clutch case 61 in front of the clutch plate disposed at the foremost end of the clutch plates 62 and 63 and the front end of the tubular portion 20a of the clutch gear 20. It is slidably arranged in the axial direction (front-rear direction) along the boss portion 61a. A portion of the internal space of the clutch case 61 in front of the piston 66 is a hydraulic oil chamber 60a.

  The rear end of the hydraulic oil passage 8b in the clutch shaft 8 is a hydraulic oil passage 61d formed in a radial oil hole in the clutch shaft 8 and a front portion of the central boss portion 61a of the clutch case 61. Is communicated with the hydraulic oil chamber 60a.

  The oil from the discharge port of the electromagnetic proportional valve 71 is supplied to the hydraulic oil chamber 60a through the hydraulic oil supply oil passage 5c, the annular groove 8a, the hydraulic oil passage 8b, and the hydraulic oil passage 61d. The piston 66 slides rearward, and the clutch plates 62 and 63 are pressed against each other between the piston 66 and the receiving plate 64, whereby the clutch gear 20 is engaged with the clutch case 61 so as not to rotate relative to the clutch case 61. The clutch shaft 8 is engaged with the clutch shaft 8 through a shaft. That is, the clutch is engaged.

  On the contrary, when the oil is released from the hydraulic oil chamber 60a, the piston 66 slides forward by the action of the spring 67, so that the clutch plates 62 and 63 are separated from each other, and the clutch is disengaged.

  The piston 66 is formed with a central boss portion 66a that is slidably fitted to the central boss portion 61a of the clutch case 61. Around the front end portion of the central boss portion 66a, a circumferential recess having a rear opening shape is formed. 60b is formed.

  On the other hand, a space is secured between the outer peripheral surface of the central boss 66a of the piston 66 and the inner peripheral surface of the cylindrical portion 20a of the clutch gear 20 surrounding the inner space of the clutch case 61. A cup-shaped canceller 68 having a front end opening shape is disposed in the space, and the inner peripheral edge of the vertical plate portion 69a formed at the rear end of the canceller 68 is located behind the rear end of the central boss portion 66a of the piston 66. It is attached to the outer peripheral surface of the center boss portion 61a.

  A lubricating oil guide plate 69 is fixed to the central boss portion 61a so as to be in contact with the vertical plate portion 69a behind the vertical plate portion 69a and is in contact with the rear end of the canceller 68. ing.

  In the canceller 68, a front end edge portion 68c surrounding the front end opening is disposed in the recess 66b of the piston 66, and an outer peripheral surface thereof is slidably fitted to an inner peripheral surface of the recess 66b. A spring 67 is interposed between the vertical plate portion of the piston 66 that defines the front end of the recess 66 b and the vertical plate portion 68 a at the rear end of the canceller 68.

  The canceller 68 is formed with a peripheral portion 68b so as to extend from the outer peripheral end of the vertical plate portion 68a to the front end edge portion 68c. The peripheral portion 68b surrounds the central boss portion 66a of the piston 66. Are arranged as follows.

  The spring 67 is disposed so as to pass through a gap between the inner peripheral surface of the peripheral portion 68b and the outer peripheral surface of the central boss portion 66a. Due to the urging force of the spring 67, the piston 66 is urged forward, that is, in the clutch disengagement direction, and the hydraulic pressure applied to the piston 66 is applied in the clutch engagement direction against the urging force of the spring 67. ing. On the other hand, the canceller 68 is always held in a state in which the vertical plate 68 a at the rear end is in contact with the lubricant guide plate 69 by the biasing force of the spring 67.

  While the hydraulic oil is being removed from the hydraulic oil chamber 60a, the front end of the piston 66 is originally held in contact with the vertical plate portion 61b of the clutch case 61 by the biasing force of the spring 67, and the clutch plates 62 and 63 are retained. Is in a separated state, that is, a state in which the clutch is separated. However, during high rotation, centrifugal oil pressure is generated in the oil that remains slightly in the hydraulic oil chamber 60 a, and this centrifugal oil pressure is in a direction (rear) in which the clutch plates 62 and 63 are pressed against the piston 66 against the spring 67. Take it. As a result, the clutch may be engaged unexpectedly, resulting in a problem that causes power loss and wear of members such as the clutch. In order to prevent this, it is conceivable to use the spring 67 having a strong biasing force, but there is a possibility that the cost is increased.

  Therefore, in the hydraulic clutch unit in the dual clutch transmission 1 according to the present application, a canceller 68 is provided, and a cancel chamber 60b facing the hydraulic oil chamber 60a in front of the piston 66 is secured between the canceller 68 and the piston 66. In addition, oil is introduced into the canceller chamber 60b to counteract the hydraulic pressure in the hydraulic oil chamber 60a, thereby preventing the unexpected pressure contact of the clutch plates 62 and 63 due to the centrifugal hydraulic pressure.

  As the oil introduced into the cancel chamber 60b, the lubricating oil supplied from the lubricating oil passage 8c in the clutch shaft 8 to the hydraulic clutch unit 60 is used. That is, in the clutch shaft 8, the radial oil hole 8 c 1 is branched from the lubricating oil passage 8 c in the axial direction, and the outer end thereof is opened at the outer peripheral surface of the clutch shaft 8. On the other hand, a radially lubricating oil hole 61e is formed in the front and rear of the central boss portion 61a of the clutch case 61, and an opening end of the lubricating oil hole 61e on the inner peripheral surface of the central boss portion 61a. Is connected to the open end of the oil hole 8c1 on the outer peripheral surface of the clutch shaft 8.

  The outer end opening of the lubricating oil passage 61e faces the inner peripheral surface of the central boss portion 66a of the piston 66, and the lubricating oil overflowing from the lubricating oil passage 61e is formed in the central boss portion 66a so as to penetrate inside and outside. In addition, the oil is introduced into the cancel chamber 60b through the lubricating oil hole 66c or the cancel oil hole 66d.

  The lubricating oil hole 66c is disposed so as to communicate with the lubricating oil hole 61e of the clutch case 61 when the piston 66 is in the clutch engagement position, and the diameter thereof is fed to the clutch plates 62 and 63 as lubricating oil. The dimensions are set so that the amount of oil can be captured.

  The cancel oil hole 66d is disposed so as to communicate with the lubricating oil hole 61e when the piston 66 is in the clutch disengagement position, and the diameter of the cancel oil hole 66d cooperates with the spring 67 and is the hydraulic oil in the hydraulic oil chamber 60a. The oil is small enough to take in oil to counteract the centrifugal oil pressure into the cancel chamber 60b.

  That is, these oil holes 66c and 66d are provided with a cancel chamber 60b that supplies only the oil corresponding to the centrifugal hydraulic pressure when the clutch is disengaged and the oil supplied to the clutch plates 62 and 63 as the lubricating oil when the clutch is engaged. It has a configuration to be introduced.

  The clutch plates 62 and 63 are disposed so as to surround the circumferential portion 68 b of the canceller 68, that is, on the radially outer side of the canceller 68. The existing lubricating oil hole 66c in the piston 66 originally lubricates the oil that overflows from the lubricating oil hole 66c to the clutch plates 62 and 63 disposed on the radially outer side through the internal space of the clutch case 60. It is arranged so that it can be supplied as oil.

  In the internal space of the clutch case 60, the canceller 68 is disposed so as to shield the clutch plates 62 and 63 from the lubricating oil holes 66c, thereby securing a cancel chamber 60b in the canceller 68. In the cancel chamber 60b, The oil overflowing from the lubricating oil hole 66c or the canceling oil hole 66d is taken in and counteracts the centrifugal hydraulic pressure of the hydraulic oil in the hydraulic oil chamber 60a. Therefore, a structure is required in which the lubricating oil is fed from the cancel chamber 60b to the clutch plates 62 and 63 shielded from the lubricating oil hole 66c by the canceller 68.

  Therefore, a part of the inner peripheral edge of the vertical plate portion 68a of the canceller 68 that contacts the outer peripheral surface of the central boss portion 61a of the clutch case 61 so that the lubricating oil overflowing from the lubricating oil passage 66c can reach the clutch plates 62 and 63 as well. Further, as shown in FIGS. 10 and 11, a radial oil groove 69a is formed in the vertical lubricating oil guide plate 69, and the notch 68d and the oil groove 69a are interposed through the notch 68d and the oil groove 69a. The oil in the canceller 68 is configured to flow out to the portion where the clutch plates 62 and 63 are disposed outside the canceller 68 in the internal space of the clutch case 60. Thereby, even if it is the structure which provided the cancellation chamber 66a in the radial direction inner side of clutch plate 62 * 63, lubricating oil can fully be supplied to clutch board 62 * 63.

50 Hydraulic pump set 50a First hydraulic pump 50b Second hydraulic pump 51 Oil passage pipe member 52 Cover plate 52a Suction oil passage 52b Discharge oil passage 53 Pump block 53a (secondary) suction oil passage 53b Hydraulic oil supply oil passage 54 Oil Road block 54a Return oil path 54b Discharge oil path 54c Communication oil path 54d Hydraulic oil supply oil path 55 Unloading on-off valve 56 Check valve

Claims (3)

In the hydraulic pump unit for supplying clutch hydraulic oil, which is a combination of two first hydraulic pumps and second hydraulic pumps that are simultaneously driven by a power source,
Regardless of the rotational speed of the power source, the oil discharged from the first hydraulic pump is supplied to the hydraulic oil chamber of the hydraulic clutch,
When the rotational speed of the power source is less than a predetermined value, the discharge oil from the second hydraulic pump is merged with the discharge oil from the first hydraulic pump,
When the rotational speed of the power source is a predetermined value or more, the discharge oil from the second hydraulic pump is returned to the suction port of the first hydraulic pump,
Hydraulic pump unit for clutch hydraulic oil supply. A hydraulic oil supply oil path extending from the discharge port of the first hydraulic pump and going to the hydraulic oil chamber of the hydraulic clutch;
An on-off valve that is controlled to open and close by a controller based on detection of the rotational speed of the power source;
A communication oil passage connecting the discharge port of the second hydraulic pump and the hydraulic oil supply oil passage to the inlet port of the on-off valve;
A return oil path from the outlet port of the on-off valve to the suction port of the second hydraulic pump;
A suction oil passage that communicates the suction ports of the first hydraulic pump and the second hydraulic pump;
The on-off valve is closed when the rotational speed of the power source is less than a predetermined value, and oil from the discharge port of the second hydraulic pump is supplied to the hydraulic oil supply oil passage through the communication oil passage. To join,
The on-off valve is opened when the rotational speed of the power source is equal to or greater than a predetermined value, and oil from the discharge port of the second hydraulic pump to the communication oil passage is transferred from the inlet port to the outlet port. Passing through the return oil path, the suction port of the second hydraulic pump, and the suction oil path, and returning to the suction port of the first hydraulic pump,
The hydraulic pump unit for supplying clutch hydraulic oil according to claim 1. A check valve that allows only an oil flow from the communication oil passage to the hydraulic oil supply oil passage when the on-off valve is closed is provided between the communication oil passage and the hydraulic oil supply oil passage. It is characterized by
The hydraulic pump unit for clutch hydraulic oil supply according to claim 2.

Images