JP2879614B2 - Engine output device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an output device mounted on an engine for extracting the output power of the engine to two shafts.

[0002]

2. Description of the Related Art For example, in a working vehicle such as a riding lawn mower, the power of a mounted engine is transmitted to wheels for use in running the vehicle, and is also transmitted to a working machine such as a lawn mower for work. Provided for machine drive. Usually, the engine has one output shaft, and in a power transmission system connected to the output shaft and separated from the engine, the power is divided into those for driving the vehicle and those for driving the work implement. JP-128620 discloses an engine configured as an integrated drive unit (engine / transaxle complex) having an output shaft for driving a vehicle and an output shaft for driving a work implement. .

In this drive unit, a transaxle is disposed in a transaxle housing in a left-right direction in a transaxle housing integrally connected to an engine housing, and pressure oil from a variable hydraulic pump provided in an engine body is introduced into the transaxle housing. The transaxle is supplied to a hydraulic motor provided, and the transaxle is driven by the hydraulic motor via a reduction mechanism and a differential mechanism also provided in the transaxle housing. On the other hand, a crankshaft of the engine extends downward from the engine body at right angles to the transaxle, and a working implement connected to a work vehicle is driven from the crankshaft via a belt.

[0004]

However, since the drive unit directly incorporates the transaxle, the installation place on the work vehicle is limited, and the drive unit can be applied only to a specific work vehicle. Lack of versatility, such as having to change specifications accordingly.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and according to the present invention, the outside of a partition plate which can be attached to a side surface of a crankcase of an engine is provided on the case wall. A case chamber is formed inside the case chamber, and a hydraulic transmission mechanism including a hydraulic pump and a hydraulic motor is provided in the case chamber; a crank direct-coupled shaft directly connected to the crankshaft of the engine; and a drive-connected to the crank direct-coupled shaft. There is provided an output device for an engine, comprising: a pump shaft of the hydraulic pump; and a transmission shaft for extracting an output of the hydraulic motor, wherein the crank direct coupling shaft and the transmission shaft project outward through the case wall. .

If this output device is mounted on the side surface of the crank of the engine via a partition plate, and the crank direct shaft is directly connected to the crankshaft of the engine, the engine power can be directly taken out from the crank direct shaft protruding from the case wall. Similarly, it is possible to take out the power shifted by the hydraulic continuously variable transmission mechanism from the transmission shaft protruding from the case wall. Therefore, when this engine is used as a prime mover of a work vehicle, the shaft directly connected to the crank may be connected to the work machine drive system, and the transmission shaft may be connected to the vehicle travel system.

By arranging three shafts in the case chamber parallel to each other and at a right angle to the partition plate, the entire output device is reduced in size, and when this output device is mounted, two output shafts, ie, cranks Since the direct connection shaft and the transmission shaft project in parallel to the same side of the engine, the installation of the engine on the work vehicle is easy, and the installation location can be selected with relatively great flexibility.

Further, this output device can be attached to a general-purpose engine, regardless of whether it is a horizontal type or a vertical type, so that an engine having one output shaft can be very easily converted into an engine having two output shafts. Therefore, the range of application is extremely wide.

[0009]

FIG. 1 is a sectional view showing an embodiment of the present invention. An output device 1 according to the present invention is mounted on an engine 2.

The engine 2 itself is an ordinary general-purpose small engine used for various applications, 3 is a cylinder head, 4 is a cylinder block, and 5 is a crankcase. The crankcase 5 includes a case body 5a formed integrally with the cylinder block 4 and opened to one side, and a case lid 5b for closing the opening.

A crankshaft 8 driven to rotate by a piston 6 via a connecting rod 7 is connected to the case body 5a and the case lid.
5b, the both ends 8a, 8b protrude outward from the crankcase 5, and the flywheel 9, the fan 10, and the recoil starter 11 are provided at the end 8a protruding from the case body 5a side. . A camshaft 12 connected to the crankshaft 8 via a gear is rotatably provided in the crankcase 5 so that an intake valve 13 and an exhaust valve 14 are operated by the camshaft 12. 15 is an intake passage, 16 is a carburetor, and 17 is an exhaust passage.

The output device 1 is formed in a hermetically sealed box shape having a case chamber 20 inside by covering the outside of a thick partition plate 18 with a case wall 19 in an airtight manner. The case cover 5b is attached to the engine 2 by fastening with bolts (not shown). In the upper part of the case chamber 20, a crank direct connection shaft 21 is rotatably supported at both ends by bearings 22 and 23 on the partition plate 18 and the case wall 19, and extends at right angles to the partition plate 18. The end of the crank direct coupling shaft 21 on the side of the partition plate 18 penetrates the partition plate 18 and is desired on the inner side surface of the partition plate 18, that is, the surface on the engine 2 side. An axial fitting hole 24 is formed in this end, and when the output device 1 is mounted on the engine 2 as described above, the end 8b of the crankshaft 8 projecting from the crankcase 5 is removed. The fitting hole 24 is fitted. In addition,
A key groove is provided in each of the end 8b and the fitting hole 24, and the end 8b is fitted into the fitting hole 24 while aligning these key grooves and interposing the key 25 therebetween. As a result, the crankshaft 8 and the crank direct connection shaft 21 are directly connected integrally, and the rotation of the crankshaft 8 is directly transmitted to the crank direct connection shaft 21. The other end of the crank direct connection shaft 21 penetrates the case wall 19 and protrudes outward.

In the case chamber 20, there is housed a hydraulic stepless transmission mechanism 28 comprising a swash plate type hydraulic pump 26 and a swash plate type hydraulic motor 27, and a pump shaft 29 of the hydraulic pump 26 and a hydraulic motor 27. The output shaft, ie, the transmission shaft 30, is rotatably supported between the partition plate 18 and the case wall 19 in parallel with the crank direct connection shaft 21. Pump shaft
29 is driven by a crank direct coupling shaft 21 via gears 31a and 31b meshing with each other, and the outer end of the transmission shaft 30 penetrates the case wall 19 and protrudes outward similarly to the crank direct coupling shaft 21.

FIG. 2 is an enlarged sectional view of the output device 1. The hydraulic pump 26 includes a cylinder block 32 mounted on a pump shaft 29 so as to rotate integrally with the pump shaft 29. The cylinder block 32 includes a plurality of cylinders 33 parallel to the pump shaft 29 which are concentric with the pump shaft 29. It is arranged at equal intervals above. A piston 35 urged rightward by a spring 34 is slidably fitted in the cylinder 33. A swash plate 36 is provided on the right side of the cylinder block 32 so as to face the cylinder block 32. The tip of the piston 35 urged by the spring 34 contacts and presses the swash plate 36, and the swash plate 36 is in contact with the back surface of the swash plate 36 via rollers 37 arranged in an annular shape. Has been received by Cylinder block
When the shaft 32 rotates with the pump shaft 29, the swash plate 36 pushed by the piston 35 rotates with the piston 35 by the rolling of the roller 37, but the surface formed by the roller 37, and thus the swash plate 36 Since the surface is inclined with respect to the axis of the pump shaft 29, a stroke movement of the piston 35 occurs in response to the rotation. The bottom of the cylinder 33 is the entrance 39
Through the opening, it opens at the left end surface of the cylinder block 32, and the left end surface is in sliding contact with a valve plate 40 of a distributor (not shown) built in the partition plate 18. Since the valve plate 40 is provided with a valve hole for communicating the inlet / outlet 39 with the oil discharge passage and the oil suction passage of the distributor at an appropriate rotation position, oil moves to the cylinder 33 by the stroke movement of the piston 35 described above. After being sucked, it is pressurized and discharged to the discharge passage.

The hydraulic motor 27 has basically the same structure as the hydraulic pump 26, and includes a cylinder block 41, a cylinder 42, a spring 43, a piston 44, and a swash plate 45. The swash plate 45 is supported by the case wall 19 via a ball 46 and a thrust plate 47. The cylinder block 41 is fixed to the transmission shaft 30. The cylinder block 41 is in sliding contact with a valve plate 48 similar to the valve plate 40 in the hydraulic pump 26, and oil is pressed into the cylinder 42 through the valve plate 48 or discharged from the cylinder 42 according to the rotational position of the cylinder 42. Then, a stroke motion is given to the piston 44.
The oil that is press-fitted into the cylinder 42 is pressure oil that is pressure-fed into the discharge passage by the hydraulic pump 26. Since the piston 44 is in contact with the swash plate 45 and is guided by the swash plate 45, the stroke movement of the piston 44 causes the cylinder block 41 to rotate, thereby rotating the transmission shaft 30.
That is, the rotation of the pump shaft 29 is transmitted to the transmission shaft 30 via the hydraulic pressure generated by the hydraulic pump 26. An oil passage communicating the hydraulic pump 26 and the hydraulic motor 27 is formed in the partition plate 18 (not shown).

The swash plate support 38 of the hydraulic pump 26 is
The swash plate support 38 is tilted by an operating device (not shown) so that the inclination angle of the swash plate 36 can be changed. If the inclination angle of the swash plate 36 changes, the discharge capacity of the hydraulic pump 26 changes, which changes the rotation speed of the transmission shaft 30.
The gear ratio between 30 can be changed continuously.

The output device 1 attached to the engine 2
The output shaft, i.e., the crank direct-coupled shaft 21 and the transmission shaft 30 extend to the outside, so that the engine power can be directly taken out of the crankshaft 8 through the crank direct-coupled shaft 21 and the hydraulic transmission mechanism 28 passes through the transmission shaft 30. The shifted engine power can be extracted. In this way 1
An engine 2 having two output shafts (crankshaft 8) can be easily converted to an engine having two output shafts, or a compact power unit having two output shafts using a general-purpose engine Can be easily configured. When the engine or power unit configured as described above is used as a prime mover of a working vehicle such as a riding lawn mower, for example, the transmission shaft 30 is connected to the traveling drive system of the vehicle, and the traveling speed is controlled by the hydraulic transmission mechanism 28. Control is performed, and the crank direct-coupled shaft 21 is connected to the working machine drive system via an appropriate deceleration mechanism if necessary.

Since the three shafts 21, 29, 30 in the case chamber 20 are arranged in parallel with each other and at right angles to the partition plate 18, the entire output device 1 is reduced in size, and
When the is mounted, the two output shafts, namely, the crank direct connection shaft 21 and the transmission shaft 30 project in parallel on the same side of the engine, so that it is easy to install the engine on the work vehicle, and the installation place is relatively large. You can choose with a degree.

As described above, the output device 1 of the present invention is connected to the crankshaft 8.
Although the description has been given of the embodiment in which the present invention is applied to a horizontal engine 2 arranged horizontally, it goes without saying that the output device of the present invention can also be applied to a vertical engine in which the crankshaft is arranged vertically.

[0020]

According to the present invention, it is possible to easily construct an excellent engine or power unit for use in a work vehicle having two output shafts using a general-purpose engine. Further, since the output device of the present invention can be easily attached to and detached from the engine, the output device can be detached from the engine and used as a single engine if necessary. Further, since the output device according to the present invention is small and the two output shafts protrude to one side of the engine when attached to the engine, and especially in the output device of claim 2, they protrude in parallel to the same side of the engine. The installation of the engine on the work vehicle is easy, and the installation location can be selected with a relatively large degree of freedom.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of the output device in FIG.

[Description of Signs] 1 ... Output device, 2 ... Engine, 3 ... Cylinder head, 4
... cylinder block, 5 ... crankcase, 6 ... piston, 7 ... connecting rod, 8 ... crankshaft, 9 ... flywheel, 10 ... fan, 11 ... recoil starter, 12 ... camshaft,
13 ... intake valve, 14 ... exhaust valve, 15 ... intake passage, 16 ... carburetor,
17 ... exhaust passage, 18 ... partition plate, 19 ... case wall, 20 ... case chamber, 21 ... crank direct connection shaft, 22, 23 ... bearing, 24 ... fitting hole,
25 ... Key, 25 ... Hydraulic pump, 27 ... Hydraulic motor, 28 ... Hydraulic continuously variable transmission mechanism, 29 ... Pump shaft, 30 ... Shift shaft, 31 ... Gear,
32 ... cylinder block, 33 ... cylinder, 34 ... spring, 35 ... piston, 36 ... swash plate, 37 ... roller, 38 ... swash plate support, 39 ... doorway, 40 ... valve plate, 41 ... cylinder block,
42 ... cylinder, 43 ... spring, 44 ... piston, 45 ... swash plate, 46 ... ball, 47 ... thrust plate, 48 ... valve plate.

Claims (2)

(57) [Claims] 1. A casing having a case wall formed by covering an outside of a partition plate attachable to a side surface of a crankcase of an engine with a case wall, and a stepless hydraulic transmission mechanism comprising a hydraulic pump and a hydraulic motor in the case chamber. A crank shaft directly connected to the crank shaft of the engine, a pump shaft of the hydraulic pump drivingly connected to the crank shaft, and a speed change shaft for extracting an output of the hydraulic motor; An output device for an engine having a shaft protruding outward through the case wall. 2. The engine output device according to claim 1, wherein the crank direct coupling shaft, the pump shaft, and the transmission shaft are arranged in parallel with each other and at right angles to the partition plate.