JP2004255964A - Power vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device having a simple constitution and compactly stored in a case, enabling easy setting of speed when switching from a rear wheel to a crawler and surely maintaining the switching state. <P>SOLUTION: This power vehicle comprises a main clutch 51 on a front part side of a middle wall 130 of a clutch housing 8, a high and low speed switching mechanism 55 on an opposite side of the middle wall 130, and a forward/backward moving switching mechanism 63 on the transmission lower side. The vehicle is provided with a switching mechanism 133 for switching a front wheel driving system to high and low speed at a position substantially overlapped with the high and low switching mechanism 55 in side surface view. The high and low speed switching mechanism 133 is switched to a low speed side when mounting the crawler 7 in place of the rear wheel 3 mounted on a rear axle 9. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a powered vehicle that can be shifted from a wheel-type traveling device to a crawler-type traveling device, and can be used for a tractor, a passenger management machine, and the like.
[0002]
[Prior art]
It is known that a power vehicle such as an agricultural tractor is used as a foil specification in a hard field such as an upland field, and is used by replacing a foil with a crawler in a soft wetland field (for example, see Patent Document 1). .
[0003]
In general, in the case of the crawler type as compared with the wheel type, the rotation speed of the front wheels must be reduced by an amount corresponding to the smaller outer diameter of the sprocket mounted on the rear axle. This is because the lead ratio of the front and rear wheels must be maintained in an appropriate state. In addition, regardless of the wheel type or the crawler type, the rotational peripheral speed on the front wheel side must be several percent higher than that on the rear wheel side or crawler side.
[0004]
[Patent Document 1]
JP-A-10-45052
[Problems to be solved by the invention]
By the way, in the above-mentioned conventional device, a high-low speed switching mechanism for equalizing the lead ratio of the front and rear traveling devices when changing from the rear wheel to the crawler is simply incorporated in the front wheel drive system. However, no consideration was given to the arrangement position, so that there was a problem that the mission case itself was large and bulky due to taking a large space in the mission case.
[0006]
[Means for Solving the Problems]
The present invention has been made in view of the above-described problems, and is intended to accommodate a high-low speed switching device in a transmission case in a compact manner. For this reason, the following technical measures were taken.
[0007]
That is, in the first aspect of the present invention, the main clutch 51 is provided on the front side of the middle wall 130 of the clutch housing 8, the high / low speed switching mechanism 55 is provided on the opposite side of the middle wall 130, and the forward / backward movement is transmitted to the lower side thereof. A powered vehicle provided with a switching mechanism 63, wherein a switching mechanism 133 for switching a front wheel drive system between a high speed and a low speed is provided at a position substantially overlapping with the high / low speed switching mechanism 55 in a side view.
[0008]
According to a second aspect of the present invention, the high-low speed switching mechanism 133 is configured to switch to a low speed side when the crawler 7 is mounted in place of the rear wheel 3 mounted on the rear axle 9. Powered vehicle.
According to a third aspect of the present invention, the switching arm 178 of the high / low speed switching mechanism 133 is provided with a traction mechanism 182 for preventing switching from a low speed to a high speed or from a high speed to a low speed. Alternatively, the motor vehicle according to claim 2 is provided.
[0009]
In the above configuration, when the tractor is used as a wheel type, the high / low speed switching mechanism is switched to a high speed side, and when the tractor is used as a crawler type, the high / low speed switching mechanism is switched to a low speed side for use.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, a description will be given of the configuration. Reference numeral 1 denotes a tractor, which is provided with a front wheel 2 and a rear wheel 3, and transmits the rotational power of an engine 4 mounted on a front part of the fuselage to a transmission 6 in a transmission case 5. The decelerated rotational power is transmitted to the front wheel 2 and the rear wheel 3.
[0011]
The tractor 1 can run on the crawler 7 instead of the rear wheel. In this embodiment, the description will be made on the assumption that the crawler 7 is worn from the beginning.
The configuration of the traveling device having the crawler 7 will be described. A sprocket 10 is detachably mounted on the rear axle 9 and a front idle wheel 12, a rear idle wheel 13 and a plurality of rolling wheels 14 are provided on the track frame 11 side.
[0012]
In this embodiment, a support mast 16 is erected upward from the outer side of the upper surface of the track frame 11, and a bearing 18 is formed on the support mast 16, and the shaft-equipped flange 19 is rotated by the bearing 18. It is movably supported. The sprocket 10 is superposed on the inner surface of the flange 19 with a shaft, and the sprocket 10 and the flange 19 are united by a plurality of bolts 20.
[0013]
The crawler 7 is wound around the two idler wheels 12, 13 and the sprocket 10, and the track frame 11 itself is configured to swing in a predetermined range in the front-rear direction around the rotation axis of the sprocket 10. I have.
The front idler wheel 12 can be adjusted to expand and contract in the front-rear direction, so that the amount of tension of the crawler 7 can be adjusted. Reference numeral 21 denotes a rail for preventing the crawler 7 from coming off. The rail 21 is formed of a hard iron round bar or the like, and is usually accommodated in the groove of the crawler 7 so that the crawler 7 does not come off when a strong force acts on the crawler 7 from the side. I have. Further, between the body and the track frame 11, there is provided a restricting member 24 for preventing the track frame 11 itself from falling down in the horizontal direction and for restricting the vertical swing amount. explain.
[0014]
The restrictor 24 includes a first pin 26 fixedly supported on the track frame 11 side, a second pin 27 fixedly supported on the fuselage side, and two swingably supported links between the pins 26 and 27. A first pin 26 is fixed to the track frame 11 horizontally and horizontally, and a second pin 27 is fixed to a lower portion of the rear axle housing 32. The members 28, 29 and the link members 28, 29 are pivotally connected to each other. It is fixed to.
[0015]
Cylindrical portions 28a, 28a, 29a, 29a are provided at both ends of the two link members 28, 29, respectively. The pins 26, 27, 30 are fitted into these cylindrical portions 28a, 29a. Therefore, when the track frame 11 swings up and down about the rotation axis of the sprocket 10, the link members 28 and 29 swing up and down while changing their relative angles.
[0016]
Further, as shown in FIG. 7, on one link member 29 side, contact portions 36 and 37 for restricting the swing of the track frame 11 from below are formed on stopper portions 34 and 35 formed at the lower part of the abdomen of the body. ing.
Hard rubbers 39 and 40 are detachably attached to the front and rear stopper portions 34 and 35, respectively, so that the swing of the track frame 11 is suppressed via the rubber. In particular, on the front side, not only the deformation of the rubber 39 but also the hitting of the iron plate 41 thereunder prevents the track frame 11 from moving upward.
[0017]
For this reason, the contact portion 36 of the link member 29 is cut so as to regulate the swing of the track frame 11 while maintaining a certain degree of accuracy.
As shown in FIG. 8, circular collars 43, 43, 44 are provided at both ends and an intermediate portion of the pivot pin 30, and the inner and outer collars 43, 43 excluding the intermediate portion have end faces of the cylindrical portions 28 a, 29 a. The collars 43 are tightened and fixed by bolts 46 with the end faces of the pivot pins 30 covered.
[0018]
Conventionally, a groove was cut outside the pivot pin 30 and measures were taken to prevent it from coming off with a C-shaped retaining ring. With such a configuration, the seal would be damaged when the seal is inserted. There was fear. However, as described above, if a method is employed in which the outer peripheral surface of the pivot pin 30 is held by the collars 43 without cutting a groove, there is no danger of damaging the seal, and the end surface of the pivot pin 30 is not damaged. It has the feature that the painting can be omitted and the production cost can be reduced.
[0019]
Such a process is the same not only for the end of the pivot pin 30 but also for the end surfaces of the first pin 26 and the second pin 27. The production cost can be reduced by using a configuration in which the color is suppressed. Is possible.
Next, the power transmission system of the tractor 1 will be described.
[0020]
The power of the engine 4 is transmitted to high and low speed gears 52 and 53 for traveling via a main clutch 51 housed in the clutch housing 8. Below these gears 52 and 53, there is provided a hydraulic multi-plate clutch 55 capable of two-stage high-low speed shifting, and constitutes a high-low switching mechanism 133.
[0021]
The low-speed gear 52 meshes with the front gear 56 of the hydraulic multi-plate clutch 55, and the high-speed gear 53 meshes with the rear gear 57 of the hydraulic multi-plate clutch 55. When the front piston accommodated in the rotary drum 59 of the hydraulic multiple disc clutch 55 is hydraulically operated, a low speed is obtained, and when the rear piston is operated, a high speed is obtained. A reverse gear 61 and a forward gear 62 are provided concentrically with the output shaft 60 behind the output shaft 60 integral with the rotary drum 59, and the reverse gear 61 is connected to a front gear 66 of a forward / reverse clutch 65 via a counter gear 64. The forward gear 62 is always meshed with the rear gear 67 of the forward / reverse clutch 65.
[0022]
When the front piston accommodated in the rotary drum 69 of the forward / reverse clutch 65 is operated, the reverse clutch is connected and the aircraft moves backward. Conversely, when the rear piston of the forward / backward clutch 65 is activated, the forward clutch is engaged. The aircraft will move forward. Reference numeral 63 indicates the forward / reverse switching mechanism as a whole.
[0023]
The forward / backward operation of the aircraft is performed by a forward / backward operation lever 72 provided below the steering handle 71. When the lever 72 is pushed forward, the aircraft goes forward, when pulled backward, it goes backward, and when it is in the middle position, it enters a neutral state. The aircraft stops.
A main transmission shaft 75 is provided on an extension of the axis of the output shaft 74 of the forward-reverse clutch 65, and a synchromesh type main transmission 78 capable of four-speed shifting is provided on the main transmission shaft 75. A counter shaft 84 is provided in parallel with the main transmission shaft 75, and four counter gears 85, 86, 87, and 88 are provided on the counter shaft 84. When the front slider 90 of the main transmission 78 is moved forward, the fourth speed of the main transmission is moved. When the rear slider 92 is moved backward, the third speed of the main transmission is moved. The first speed of the main speed is obtained by moving the first speed.
[0024]
A sub transmission 95 of a constant mesh type is provided at the lower side of the transmission of the main transmission 78 so that a three-stage shift can be performed by appropriately operating the front and rear sliders 96 and 97.
In this embodiment, when the front slider 96 is moved forward, a high speed H of the sub-shift is obtained, and when it is moved backward, the middle (M) of the sub-shift is obtained, and when the rear slider 97 is moved rearward. It is configured such that a low (L) of the subtransmission can be obtained.
[0025]
In this manner, the rotational power having been shifted in a total of 24 stages, that is, two stages of high and low speeds, four stages of main transmission, and three stages of subtransmission is transmitted to the drive pinion shaft 98 as the final shaft.
The rotation of the gear 99 fixed to the drive pinion shaft 98 is transmitted to the gear 103 on the front wheel power take-out shaft 105 via the two-stage gear 101 rotatably fitted to the PTO drive shaft 100. It is configured as follows.
[0026]
A front wheel speed increasing device 107 for increasing the rotation speed of the front wheel 2 is provided on an extension of the front wheel power take-off shaft 105, and a rear piston provided in a rotary drum 108 of the front wheel speed increasing device 107 is operated. And the front wheel power take-out shaft 105 and the output shaft 110 of the front wheel speed increasing device 107 are directly connected to each other to be in a standard four-wheel drive state. Conversely, when the front piston is operated, the gear is sequentially transmitted through the gears 111, 112, 113 and 114. The increased rotation is transmitted to the output shaft 110. The operation of the front wheel speed increasing device 107 is the same as that of the conventional device, and the description is omitted. However, the switching is performed in conjunction with the operation of the steering handle 71, and the vehicle is in a standard four-wheel drive state during low-speed operation and straight running, Only when turning on the shore, the rotational peripheral speed of the front wheel 2 is configured to be approximately twice as high as that of the rear wheel.
[0027]
A geared shaft 118 is connected to the front end of the output shaft 110 of the front wheel speed increasing device 107 via a coupling 116. The manner of supporting the geared shaft 118 will be described.
A metal 124 is attached to the vertical wall 122 of the spacer transmission case 120 connected to the clutch housing 8 by fitting with a spigot, and the gear 124 is provided by two front and rear bearings 125 and 126 provided on the inner peripheral surface of the metal 124. The attached shaft 118 is rotatably supported.
[0028]
A reduction shaft 128 is inserted into the recess of the geared shaft 118, supports the rear end of the shaft 128 via a needle bearing 129, and has a bearing 132 provided on the middle wall 130 of the clutch housing 8 on the front side. It is configured to be rotatably supported by. The geared shaft 118 is provided with a gear 134 and a tooth 135, while a reduction gear 137 is loosely fitted on the reduction shaft 128. The gear 134 meshes with the gear 140 at the rear of the counter shaft 139, and the reduction gear 137 meshes with the front gear 141 on the counter shaft 139 at all times. When the slider 144 is moved to the rear side, the teeth provided on the inner periphery of the slider 144 mesh with the teeth 135 on the geared shaft 118 side to be directly connected. Conversely, when the slider 144 is moved to the front side, the rotation reduced to １ ／ through the gear 134, the gear 140, the front gear 141, and the reduction gear 137 is taken out from the shaft 128 in this order.
[0029]
When the rear wheel is mounted on the rear axle 9 and used as a wheel type, the slider 144 is moved rearward. When the sprocket 10 is mounted on the rear axle 9 and the crawler 7 is driven, the slider 144 is moved forward. The rotation transmitted to the front wheels 2 is reduced to about 1/2.
[0030]
Although not shown, a universal joint shaft is attached to the front end of the reduction shaft 128, and the front end of the universal joint shaft is connected to an input shaft for front wheel drive which is mounted on the front axle housing so as to protrude rearward from the rear end. The parts are detachably connected.
Next, the configuration of the PTO drive system will be briefly described. The power of the engine 4 is transmitted to the PTO clutch 147 independent of the main clutch 51 for traveling.
[0031]
That is, the power is sequentially transmitted to the input portion of the PTO clutch 147 via the gear 149, the gear 150, the gear 151, and the gear 152, and when the PTO clutch 147 is turned on to be in the connected state, the PTO output shaft 155 is rotationally driven.
A clutch mechanism 157 that switches the rotation direction of the PTO output shaft 155 in the forward or reverse direction is provided on the rear portion of the vertical wall 122 of the spacer transmission case 120. When the slider 158 is moved to the front side, the rotation of the PTO output shaft 155 is transmitted to the PTO drive shaft 100 as it is, and the PTO drive shaft 100 rotates in the normal rotation direction.
[0032]
On the other hand, when the slider 158 is moved backward, the rotation of the PTO output shaft 155 is transmitted to the PTO drive shaft 100 via the gear 161, the gear 162, the gear 163, the gear 164, and the gear 165 in order. are doing.
Although not described, the rotation of the PTO shaft projecting rearward at the rear of the transmission case 5 can be taken in three steps for both forward rotation and reverse rotation by the transmission 167 housed at the rear of the transmission case 5. I have.
[0033]
Next, a switching mechanism of the slider 144 and a restraining mechanism thereof will be described with reference to FIGS. The shifter 168 for moving the slider 144 in the front-rear direction slides back and forth on the shifter stay 169 to switch the speed reduction device. I have. The locking pin 172 is bent in an L-shape when viewed from the back, and the upper end thereof is fixed to the inner end of the pivot pin 176 inserted into the through hole 174 of the clutch housing 8.
[0034]
A switching arm 178 is fixed to the outer end of the rotation pin 176, and the slider 144 is moved in the front-rear direction by rotating the switching arm 178 in the front-rear direction.
A stud bolt 179 is embedded in the outer wall of the clutch housing 8, and a long nut 180 is screwed into the stud bolt 179, and a restraint bolt 182 is attached to the tip of the long nut 180. As shown in FIG. 3, the embedding position of the restraint bolt 182 is set to a position where after the arm 178 is switched, it is restrained so as not to move from that position.
[0035]
That is, in FIG. 3, the solid line position (a) of the switching arm 178 is the position of the wheel specification, and the dotted line (b) is the switching position of the crawler specification. When switching, the traction bolt 182 is removed, the arm 178 is rotated in the front-rear direction, and after the rotation, the traction bolt 182 is screwed into the long nut 180 again.
[0036]
As described above, by attaching the restraining bolt 182 after switching the arm 178, the switching arm 178 can be surely restrained without inadvertently moving. In FIG. 4, reference numeral 184 denotes a lock nut. Reference numeral 185 denotes a mounting bolt for fixing the support metal 124 to the spacer transmission case 120. FIGS. 5 and 6 show the position of the switching unit. Fuel tanks 186, 186 are provided on both left and right sides of the transmission case 5, and a switching arm 178 is provided between the right fuel tank 186 and the transmission case 5, and as shown in FIG. The configuration is such that the switching arm 178 is positioned higher than the bottom.
[0037]
Finally, the improvement of the hydraulic circuit of the forward / reverse clutch 65 constituting the hydraulic forward / reverse switching mechanism 63 will be described with reference to FIGS.
FIG. 9 is a conventional one in which FIG. 10 is improved, and the same or similar components are denoted by the same reference numerals, and those having different configurations are denoted by different reference numerals.
[0038]
Explaining the conventional configuration, the hydraulic oil sent from the hydraulic pump 200 enters a forward / reverse switching control valve 202, where it is switched and flows into the forward clutch chamber F or the reverse clutch chamber R, and releases the clutch. The aircraft was moving forward and backward by connecting. When switching from forward to reverse or from reverse to forward, the control valve 202 passes through the neutral position, but one throttle 210 is interposed in the circuit 205 returning to the tank 203 (also serving as a transmission case). When one of the pressures is released and the other pressure is raised by the operation of the throttle 210, a part of the released oil may enter the chamber on the opposite side without returning to the tank 203, and as a result, the clutch on the opposite side may be disengaged. The connection time becomes extremely short, and a surge pressure is generated, which causes a shock when the clutch is connected.
[0039]
FIG. 10 shows a part of the circuit improved in view of such a problem, in which two throttles 214 are provided at the neutral position of the control valve 202.
By adopting such a simple configuration, the timing of switching the clutch connection is slightly delayed, and the switching from forward to reverse or from reverse to forward can be smoothly performed.
[0040]
【The invention's effect】
According to the first aspect of the present invention, the main clutch 51 is provided on the front side of the middle wall 130 of the clutch housing 8, the high / low speed switching mechanism 55 is provided on the opposite side of the middle wall 130, and the forward / reverse switching mechanism is provided on the lower side of the transmission. In a powered vehicle provided with a switching mechanism 63, a switching mechanism 133 for switching a front wheel drive system between a high speed and a low speed is provided at a position substantially overlapping with the high / low speed switching mechanism 55 in a side view. The switching mechanism 133 can be provided in the same space by effectively utilizing the 55 arrangement parts, and these mechanisms can be compactly housed in the case.
[0041]
According to a second aspect of the present invention, the high / low speed switching mechanism 133 is switched to a low speed side when the crawler 7 is mounted in place of the rear wheel 3 mounted on the rear axle 9. Since the power vehicle described above is used, the lead ratio between the front traveling device and the rear traveling device can be optimally set regardless of the wheel type or the crawler type.
[0042]
According to a third aspect of the present invention, the switching arm 178 of the high / low speed switching mechanism 133 is provided with a check mechanism 182 for preventing switching from low speed to high speed or from high speed to low speed. According to the power vehicle of the first or second aspect, the state can be reliably maintained after the switching operation by the high / low speed switching mechanism 133, and there is no possibility that the vehicle is erroneously switched during the operation.
[Brief description of the drawings]
FIG. 1 is a side view of a tractor.
FIG. 2 is a sectional view of a mission.
FIG. 3 is a side view of a main part.
FIG. 4 is a front view of a main part partially cut away.
FIG. 5 is a side view of a main part.
FIG. 6 is a plan view of a main part.
FIG. 7 is a side view of a main part.
FIG. 8 is a rear view of a main part partially cut away.
FIG. 9 is a hydraulic circuit diagram.
FIG. 10 is a hydraulic circuit diagram.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Tractor 2 Front wheel 4 Engine 5 Transmission case 6 Transmission 7 Crawler 8 Clutch housing 9 Rear axle 10 Sprocket 11 Track frame 12 Front free wheel 13 Rear free wheel

Claims (3)

A power vehicle in which the main clutch 51 is provided on the front side of the middle wall 130 of the clutch housing 8, the high / low speed switching mechanism 55 is provided on the opposite side of the middle wall 130, and the forward / reverse switching mechanism 63 is provided on the lower side of the transmission. , A switching mechanism 133 for switching the front wheel drive system between high and low speeds at a position substantially overlapping with the high and low speed switching mechanism 55 in side view. The power vehicle according to claim 1, wherein the high / low speed switching mechanism (133) is switched to a low speed side when the crawler (7) is mounted instead of the rear wheel (3) mounted on the rear axle (9). The switching arm (178) of the high / low speed switching mechanism (133) is provided with a check mechanism (182) for preventing switching from low speed to high speed or from high speed to low speed. Powered vehicle.

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