JP2009208552A - Tractor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To considerably improve functions, only if changing a center case. <P>SOLUTION: This center case 13 of a transmission case 1 is internally fitted with a sub transmission 7, a PTO clutch 10 and a double speed transmission device 9, and journals each of input shaft 15 and output shaft 16 transmitted from a main transmission 5, a PTO clutch input shaft 17, a transmission shaft 19 transmitted from a differential pinion shaft 18 and a power take out shaft 20 for driving an axle. The sub transmission 7 is capable of performing multistage shifts by a selective connection of transmission gears 21-27 provided on the input shaft 15, the output shaft 16 and the PTO clutch input shaft 17. The double speed transmission device 9 shifts power transmitted to the axle to high and low or cuts the power by a selective connection or unconjugation of standard gears 28 and 29 provided in the transmission shaft 19 and the power take out shaft 20, double speed gears 30 and 31, and a pair of hydraulic clutches 9a and 9b. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention provides a transmission case that shifts the power of an engine and transmits it to an axle, a PTO clutch that turns on and off the power that is transmitted from the engine to the PTO shaft, and the power that is transmitted to the front axle to a high or low speed. The present invention relates to a tractor equipped with a double speed transmission for cutting.

A transmission gearbox that shifts the power of the engine and transmits it to the axle in the transmission case, a PTO device that shifts the power transmitted from the engine to the PTO shaft, and a double speed transmission that shifts or cuts the power transmitted to the front axle to high or low A tractor with a built-in device is known (see, for example, Patent Document 1). In recent years, in this kind of tractor, in order to further improve the functionality of the tractor, multiple speed transmissions, addition of independent PTO (PTO clutch), double speed transmission consisting of a pair of friction multi-plate hydraulic clutches Equipment equipment is being studied.
Japanese Patent No. 3786679

  However, if the transmission is reconfigured to simultaneously perform multistage travel transmissions, the addition of an independent PTO (PTO clutch), and the installation of a double speed transmission device consisting of a pair of friction multi-plate hydraulic clutches, Not only does the mold cost occur, but there is a problem that the transmission case is forced to be enlarged or the assemblability is lowered due to a significant change in the assembly process.

  The present invention has been created in order to solve these problems in view of the above-described circumstances, and includes a transmission case configured by connecting a clutch housing case, a center case, and a differential case to an engine. A tractor equipped with a traveling transmission that shifts power and transmits it to the axle, a PTO clutch that turns on and off the power that is transmitted from the engine to the PTO shaft, and a double speed transmission that shifts or cuts the power that is transmitted to the front axle at high and low levels The travel transmission includes a main transmission and a high / low transmission configured using a frictional multi-plate hydraulic clutch, and an auxiliary transmission configured using a constantly meshing gear transmission. Of these, the main transmission and the high / low transmission are respectively a clutch housing case and a differential case. On the other hand, the auxiliary transmission is installed in the center case, and the center case is provided with a PTO clutch and a double speed transmission device configured by using a frictional multi-plate hydraulic clutch, and a main transmission. An input shaft and an output shaft transmitted from the device, a PTO clutch input shaft, a transmission shaft transmitted from the differential pinion shaft, and a power take-off shaft that drives the front axle are each supported, of which the auxiliary transmission is Multi-speed transmission is possible by selective coupling of transmission gears provided on the input shaft, output shaft, and PTO clutch input shaft, and the double speed transmission device is a standard and double speed gear provided on the transmission shaft and the power take-off shaft and a pair of hydraulic pressures It is characterized in that the power transmitted to the front axle is shifted to high or low or disconnected by selective coupling or non-coupling of the clutch. In this way, among the clutch housing case, the center case, and the differential case constituting the transmission case, the clutch housing case and the differential case follow the conventional case, and only the center case is changed. , Increase the functionality by adding independent PTO (PTO clutch), and equipped with a double speed transmission device consisting of a pair of friction multi-plate hydraulic clutches, providing a highly functional transmission at low cost can do. In addition, the auxiliary transmission installed in the center case uses a free space on the PTO clutch input shaft to arrange the transmission gears, and the standard and double gears that are selectively coupled to the pair of hydraulic clutches of the double speed transmission device are Since it is arranged on the dedicated transmission shaft, the auxiliary transmission, the PTO clutch, and the double speed transmission can be compactly installed to prevent the center case from becoming large and provide a transmission that is excellent in assemblability.

  Next, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, T is an agricultural tractor, and a transmission case 1 is mounted on the tractor T. As shown in FIGS. 2 to 5, the transmission case 1 inputs the power of the engine E via the main clutch mechanism 2, and branches the input power into the travel power transmission path 3 and the PTO power transmission path 4. . The travel power transmission path 3 is provided with a plurality of transmissions for shifting the travel power in multiple stages. The transmission provided in the travel power transmission path 3 is configured using a frictional multi-plate hydraulic clutch, and is always meshed with a hydraulic clutch transmission that does not require the main clutch mechanism 2 on the transmission upper side to be cut off during a shift operation. And a mesh type transmission that requires the main clutch mechanism 2 to be disengaged during a shift operation. The combination of the hydraulic clutch type transmission and the mesh type transmission allows the driving power to be reduced. Multi-speed shifting is performed.

  More specifically, the traveling power transmission path 3 is configured using a friction multi-plate hydraulic clutch, and is configured using a main transmission 5 that performs four-speed shifting, and a friction multi-plate hydraulic clutch. A forward / reverse switching device 6 that performs forward / reverse switching of traveling power, a continuously-meshing gear transmission, and a sub-transmission device 7 that performs three-stage shifting, and a friction multi-plate hydraulic clutch. And a high / low transmission 8 that performs two high / low speed shifts, and a combination of shifts by the main transmission 5, the sub transmission 7, and the high / low transmission 8 enables a 24-speed traveling shift, Forward / reverse switching by the forward / reverse switching device 6 is possible. That is, in the transmission case 1, a multistage travel transmission is achieved.

  The traveling power changed by the main transmission 5, the sub transmission 7, and the high / low transmission 8 is transmitted to the front axle and the rear axle. The power transmission path to the front axle is provided with a double speed transmission device 9 that shifts or cuts the power transmitted to the front axle at a high or low level, and the front wheel at the time of turning is changed by shifting or cutting the power by the double speed transmission device 9. Switching between double speed drive, 4WD and 2WD is performed. The double speed transmission device 9 is configured using a frictional multi-plate hydraulic clutch, thereby enabling smooth shifting and disconnection.

  The PTO power transmission path 4 is provided with a PTO clutch 10 configured using a frictional multi-plate hydraulic clutch and a PTO transmission 11 configured using a constantly meshing gear transmission. An independent PTO power transmission system that is not influenced by the state, that is, a PTO power transmission path 4 of an independent PTO specification is configured.

  As described above, the transmission case 1 is composed of a multi-stage travel transmission, the addition of an independent PTO (PTO clutch 10), and a pair of friction multi-plate hydraulic clutches in order to further improve the functionality of the tractor T. The equipped double speed transmission device 9 is realized. Conventionally, in order to add these equipment at the same time, it is necessary to reconstruct the transmission, which not only incurs new mold costs, but also necessitates an increase in the size of the transmission case 1 or a significant change in the assembly process. As a result, there was a problem that the assemblability deteriorated.

  Therefore, the transmission case 1 according to the embodiment of the present invention is configured by connecting a clutch housing case 12, a center case 13, and a differential case 14, and the power of the engine E is transmitted to the transmission case 1. A traveling transmission that shifts and transmits the power to the axle, a PTO clutch 10 that turns on and off the power transmitted from the engine E to the PTO shaft, and a double speed transmission 9 that shifts or disconnects the power transmitted to the front axle at high and low are provided. In this case, the traveling transmission device includes a main transmission device 5 and a height transmission device 8 that are configured using a frictional multi-plate hydraulic clutch, and an auxiliary transmission device 7 that is configured using a constantly meshing gear transmission. Of these, the main transmission 5 and the high / low transmission 8 are respectively a clutch housing case 12 and a differential. The auxiliary transmission 7 is housed in the center case 13, while the center case 13 further includes the PTO clutch 10 and the double speed transmission 9 that are configured using a friction multi-plate hydraulic clutch. , The input shaft 15 and the output shaft 16 transmitted from the main transmission 5, the PTO clutch input shaft 17, the transmission shaft 19 transmitted from the differential pinion shaft 18, and the power take-off shaft 20 for driving the front axle. Of these, the auxiliary transmission 7 is capable of multi-speed shifting by selective coupling of transmission gears 21 to 27 provided on the input shaft 15, the output shaft 16, and the PTO clutch input shaft 17. The transmission 9 includes a standard gears 28 and 29 and double speed gears 30 and 31 provided on the transmission shaft 19 and the power take-off shaft 20 and a pair of hydraulic clutches 9a and 9b. The bound or unbound, the motive power transmitted to the front axle is arranged to shift or cut height.

  If it does in this way, clutch housing case 12 and differential case 14 will follow the conventional case among clutch housing case 12, center case 13, and differential case 14 which constitute transmission case 1, and will change only center case 13. Therefore, it is possible to cope with the increase in functions by the multi-speed traveling transmission, the addition of the independent PTO (PTO clutch 10), the equipment of the double speed transmission device 9 composed of a pair of friction multi-plate hydraulic clutches, etc. A highly functional transmission can be provided at low cost. In addition, the sub-transmission device 7 housed in the center case 13 has the transmission gears 26 and 27 arranged using the empty space on the PTO clutch input shaft 17, and the pair of hydraulic clutches 9 a and 9 b of the double speed transmission device 9. Since the standard gears 28 and 29 and the double speed gears 30 and 31 that are selectively coupled to each other are disposed on the dedicated transmission shaft 19, the auxiliary transmission 7, the PTO clutch 10, and the double speed transmission 9 are compactly housed in the center case 13. It is possible to provide a transmission excellent in assembling performance while preventing an increase in size.

  The PTO clutch 10 is configured by using a frictional multi-plate hydraulic clutch operated by hydraulic pressure, and between a clutch hub 32 provided on the input shaft 17 and a clutch drum 34 that is spline-engaged with the clutch shaft 33. Power is turned on and off by contacting and separating the provided friction plate 35. When the PTO clutch 10 is constituted by a frictional multi-plate hydraulic clutch, the pressure drum is tilted (eccentric) due to the supply and discharge of pressure oil to and from the hydraulic clutch via the sliding surface of the transmission case 1 and the clutch drum 34. ) Occurs, the sliding surface (seal portion 36) of the clutch drum 34 and the transmission case 1 is damaged, and connection failure of the PTO clutch 10 may occur due to pressure loss due to seal leakage.

  Therefore, in the transmission case 1 according to the embodiment of the present invention, the power transmitted from the engine E to the PTO shaft is turned on and off by the PTO clutch 10, and the PTO clutch 10 is a friction multi-plate hydraulic clutch operated by hydraulic pressure. In configuring, the PTO clutch 10 is provided between the input shaft 17 supported by the first bearing 37 provided in the transmission case 1 and the clutch shaft 33 supported by the second bearing 38. The clutch shaft 33 is further pivotally supported by a third bearing 39 provided behind the second bearing 38. In this way, since the clutch shaft 33 is pivotally supported at two locations, the clutch drum 34 rotating around the clutch shaft 33 can be prevented from falling, and as a result, the seal portion 36 is damaged due to the clutch drum 34 falling. And the malfunction of the PTO clutch 10 due to seal leakage can be avoided.

  The transmission case 1 is configured by connecting a clutch housing case 12, a center case 13, and a differential case 14. Among these, the center case 13 includes the PTO clutch 10 and is mounted on the rear portion of the clutch housing case 12. The first bearing 37 provided on the lid 40, the second bearing 38 provided on the intermediate wall 13a formed on the center case 13, and the first provided on the lid 41 mounted on the front portion of the differential case 14. The input shaft 17 and the clutch shaft 33 are supported by three bearings 39. In this way, when configuring the tractor T of the specification without mounting the PTO clutch 10, by changing only the configuration of the center case 13 without changing the configuration of the front and rear clutch housing case 12 and the differential case 14, Not only can a variety of transmissions be provided, but when the PTO clutch 10 is disassembled and repaired, if the space between the clutch housing case 12 and the center case 13 is divided, the PTO clutch 10 can be easily taken out and maintained. . Furthermore, since the third bearing 39 is provided using the lid 41 of the differential case 14, it is not necessary to provide a special shaft support member.

  The tractor T of this embodiment is configured with a hydraulic circuit as shown in FIG. This hydraulic circuit includes two hydraulic pumps P1 and P2, operates the double speed transmission device 9, the lift cylinder 42 and the lift rod cylinder 43 with the hydraulic pressure supplied from one hydraulic pump P1, and from the other hydraulic pump P2. The steering unit 44, the main transmission 5, the forward / reverse switching device 6, the high / low transmission 8, the PTO clutch 10, and the automatic brake turning device 45 are operated by the supplied hydraulic pressure. In FIG. 6, reference numerals 46 to 49 are electromagnetic valves for selectively turning on and off the respective hydraulic clutches of the main transmission device 5, and reference numeral 50 is for selectively connecting and disconnecting the respective hydraulic clutches of the forward / reverse switching device 6. The manual valve 52 is an electromagnetic valve for selectively engaging / disengaging each hydraulic clutch of the high / low speed transmission 8, and the numeral 53 is an electromagnetic valve for engaging / disengaging the hydraulic clutch of the PTO clutch 10.

  In the case of configuring the hydraulic circuit as described above, an oil passage is formed in the intermediate wall or lid of the transmission case 1, and pressure oil is supplied to and discharged from the traveling transmission device and the PTO clutch 10 through the oil passage. However, since the oil passage is formed in the intermediate wall and lid of the transmission case 1 by machining, in the case of the transmission case 1 where there are many pressure oil supply and discharge targets, there are a plurality of members (case and lid). ) And processing while changing the surface of the case, there is a problem that the manufacturing cost increases. In addition, since the valve blocks of the direction switching valve for supplying the pressure oil to the oil passage are also scattered at a plurality of locations of the transmission case 1, there is a problem that the member cost is increased.

  Therefore, the transmission case 1 according to the embodiment of the present invention is configured by connecting the clutch housing case 12, the center case 13, and the differential case 14, and is hydraulically operated to shift the power of the engine E and transmit it to the axle. In the interior of the transmission and the hydraulically operated PTO clutch 10 that turns on and off the power transmitted from the engine E to the PTO shaft, the main transmission 5 and the main transmission 5 are used as the traveling transmission. And a hydraulic clutch type high / low transmission 8 for further shifting the power, the main transmission 5 is dispersed in the clutch housing case 12, the high / low transmission 8 is dispersed in the differential case 14, and the PTO clutch 10 is dispersed in the center case 13. And the interior of the differential case 14 is high. The differential pinion shaft 18, which is the clutch shaft of the transmission 8, is extended to the hydraulic joint 13 b formed on the intermediate wall 13 a of the center case 13, and the supply and discharge of pressure oil to the high / low transmission 8 is transferred to the intermediate wall 13 a and the differential pinion shaft 18. On the other hand, the clutch drum 34 of the PTO clutch 10 is connected to the hydraulic joint portion 13c formed on the intermediate wall 13a of the center case 13 while the oil passage 18a is formed. Supply and discharge are performed through an oil passage 34 a formed in the intermediate wall 13 a and the clutch drum 34. In this way, an oil passage for supplying and discharging pressure oil to the high / low speed transmission 8 and the PTO clutch 10 can be provided in the common intermediate wall 13a of the center case 13, so that the oil passage is machined. The number of man-hours can be reduced, and the production cost can be reduced. In addition, illustration of the oil path formed in the intermediate wall 13a is abbreviate | omitted.

  Further, the oil passage for the high / low speed transmission and the PTO clutch formed in the intermediate wall 13a of the center case 13 is preferably communicated with a single valve block 54 mounted on one side of the center case 13 in the left-right direction. In this way, the valve block 54 for the high / low speed transmission and the PTO clutch can be used in common, so that the member cost can be reduced and the cost of the transmission can be reduced.

  According to the present embodiment configured as described above, the transmission that transmits the power of the engine E to the axle is transmitted to the transmission case 1 configured by connecting the clutch housing case 12, the center case 13, and the differential case 14. In a tractor T equipped with a transmission, a PTO clutch 10 that turns on and off the power transmitted from the engine E to the PTO shaft, and a double speed transmission 9 that shifts or cuts the power transmitted to the front axle at high and low, And a main transmission 5 and a high / low transmission 8 configured using a frictional multi-plate hydraulic clutch, and a sub-transmission 7 configured using a constantly meshing gear transmission. The device 5 and the high / low speed change device 8 are respectively mounted in the clutch housing case 12 and the differential case 14. On the other hand, the auxiliary transmission 7 is housed in a center case 13, and the center case 13 is further equipped with a PTO clutch 10 and a double-speed transmission 9 that are configured by using a frictional multi-plate hydraulic clutch, An input shaft 15 and an output shaft 16 transmitted from the transmission 5, a PTO clutch input shaft 17, a transmission shaft 19 transmitted from the differential pinion shaft 18, and a power take-off shaft 20 that drives the front axle are respectively supported. Of these, the sub-transmission device 7 is capable of multi-stage transmission by selective coupling of the transmission gears 21 to 27 provided on the input shaft 15, the output shaft 16 and the PTO clutch input shaft 17, and the double speed transmission device 9 By selectively connecting or disconnecting the standard gears 28 and 29 and the double speed gears 30 and 31 provided on the shaft 19 and the power take-off shaft 20 and the pair of hydraulic clutches 9a and 9b, Since the power transmitted to the axle is configured to be shifted or disconnected at a high or low level, the clutch housing case 12 and the differential case 14 out of the clutch housing case 12, the center case 13 and the differential case 14 constituting the transmission case 1 are By following the conventional case and changing only the center case 13, a multi-speed transmission device comprising a multi-stage travel transmission, adding an independent PTO (PTO clutch 10), and a pair of friction multi-plate hydraulic clutches Therefore, it is possible to provide a highly functional transmission at a low cost. In addition, the sub-transmission device 7 housed in the center case 13 has the transmission gears 26 and 27 arranged using the empty space on the PTO clutch input shaft 17, and the pair of hydraulic clutches 9 a and 9 b of the double speed transmission device 9. Since the standard gears 28 and 29 and the double speed gears 30 and 31 that are selectively coupled to each other are disposed on the dedicated transmission shaft 19, the auxiliary transmission 7, the PTO clutch 10, and the double speed transmission 9 are compactly housed in the center case 13. It is possible to provide a transmission excellent in assembling performance while preventing an increase in size.

It is a perspective view of a tractor. It is a side view which shows the whole transmission case. It is sectional drawing which shows the whole transmission case. It is sectional drawing which shows the intermediate part of a transmission case. It is sectional drawing which shows the PTO clutch incorporating part of a transmission case. It is a hydraulic circuit diagram which shows the hydraulic structure of a tractor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transmission case 5 Main transmission 6 Forward / reverse switching device 7 Sub transmission 8 High / low transmission 9 Double speed transmission 10 PTO clutch 12 Clutch housing case 13 Center case 14 Differential case 15 Input shaft 16 Output shaft 17 Clutch input shaft 18 Differential pinion shaft 19 Transmission shaft 20 Power take-off shaft E Engine T Tractor

Claims (1)

A transmission gearbox that shifts engine power and transmits it to the axle in a transmission case configured by connecting a clutch housing case, a center case, and a differential case, and a PTO clutch that turns on and off the power transmitted from the engine to the PTO shaft In a tractor equipped with a double speed transmission device that shifts or cuts the power transmitted to the front axle to high or low,
The traveling transmission includes a main transmission and a high / low transmission configured using a frictional multi-plate hydraulic clutch, and a sub-transmission configured using a constantly meshing gear transmission, The main transmission and the high / low transmission are respectively installed in the clutch housing case and the differential case, while the auxiliary transmission is provided in the center case, and the center case is configured by using a friction multi-plate hydraulic clutch. Power PTO clutch and double speed transmission, and input shaft and output shaft transmitted from the main transmission, PTO clutch input shaft, transmission shaft transmitted from the differential pinion shaft, and power take-out for driving the front axle And the auxiliary transmission is a shift provided on the input shaft, the output shaft, and the PTO clutch input shaft. Multi-speed transmission is possible by selective coupling of the vehicle, and the double speed transmission is a power transmission to the front axle by selective coupling or non-coupling of standard and double speed gears and a pair of hydraulic clutches provided on the transmission shaft and the power take-off shaft. A tractor characterized in that it is configured to shift or cut the wheel at a high or low level.

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