JPS633850Y2 - - Google Patents

Description

[Detailed description of the invention] This invention has the following features in order to simplify the mounting structure of the oil filter and the piping structure for it.
An oil filter comprising a connection surface on one of the outer surfaces of corner portions of a cast transmission case that are substantially orthogonal to each other, forming an annular first connection port and a second connection port surrounded by the first connection port. is attached so that the connecting surface is in close contact with the outer surface of the one in an oil-tight state, and communicates with each of the first connecting port and the second connecting port within the thickness of the transmission case. The present invention relates to a drive unit for a working vehicle in which an L-shaped oil passage is formed such that both ends thereof open to the outer surface of the other.

In forming the L-shaped oil passage within the thickness of the transmission case in the drive section structure of the work vehicle mentioned above,
The L-shaped oil passages are formed perpendicularly to both outer surfaces forming the corner, and the openings of both L-shaped oil passages formed on the outer surface on which the oil filter is not attached are set at predetermined positions. It is required that they be formed at intervals greater than the interval.

That is, if the oil passage is drilled in an inclined position relative to the outer surface, drilling becomes difficult, and in order to solve this processing problem, even if a boss portion for drilling is provided protruding from the outer surface, This is because the drilling process becomes complicated, such as having to hold the transmission case in an inclined position relative to the drilling awl, and also because both oil passages formed on the outer surface of the side where the oil filter is not attached are This is because unless the openings are formed at regular intervals, it will be difficult to connect and assemble the piping structure to the openings and to perform maintenance.

Therefore, in the drive section structure described above, in order to form an L-shaped oil passage within the thickness of the transmission case, conventionally, the first oil passage 23a' for the first connection port is formed as shown in FIG. The oil filter is formed in an L-shape at the position closest to the outer surface on the side where the oil filter is not installed, and the second oil passage 23b' for the second connection port is formed so as to bypass the first oil passage 23a'. The wall thickness of the corner portion of the transmission case C for forming the second oil passage 23b' is increased, and this causes a problem in that the thick wall portion is prone to cracking due to residual stress etc. during the transmission case casting process. Ta.

In other words, since the first connection port of the oil filter 17 that connects to the first oil path 23a' is formed in an annular shape, the position closest to the outer surface on which the oil filter is not attached is removed, and the first Oil road 2
3a' and the second oil passage 23b' without wrapping each other, and in a posture perpendicular to the outer surfaces of both of the corners forming the corner, along the wall thickness along the outer surface of the side where the oil filter is attached. Although it is possible to form the oil passages in parallel, since the distance between the first and second connection ports formed on the oil filter is generally narrow, simply forming the oil passages in parallel will cause the openings of the oil passages to overlap. If it is not possible to secure this distance, or if the distance between the openings is widened in an attempt to secure this distance, the holes must be drilled from the outside surface on the side where the oil filter is not installed, diagonally to this outside surface. Since the above-mentioned problem in drilling occurs, it is necessary to form both L-shaped oil passages in a plane perpendicular to both outer surfaces, as shown in Figure 4. This is because it was necessary to form the second oil passage 23b' so as to bypass the first oil passage 23'.

The purpose of the present invention is to improve the arrangement of both oil passages in a rational and simple manner, in view of the above-mentioned conventional situation.
The aim is to make the wall thickness of the corners of the transmission case as small as possible.

The characteristic configuration of the present invention is that, in the drive unit of the work vehicle mentioned above, the oil passage for the first connection port is formed to have a wall thickness along the outer surface of the other side, and the oil passage for the second connection port is formed in the one side. The reason is that it is formed within the wall thickness along the outer surface, and its functions and effects are as follows.

That is, when the oil filter is attached to the outer surface of the corner of the transmission case, the annular first connection port is located closest to the outer surface of the transmission case on which the oil filter is not attached.
The L-shaped oil passage for the connection port is formed within the wall thickness along this outer surface, and the oil passage for the other second connection port is formed within the wall thickness along the outer surface on which the oil filter is attached. In other words, L-shaped oil passages must be formed perpendicular to both outer surfaces forming the corner, and both L-shaped oil passages must be formed on the outer surface of the side where the oil filter is not attached. As shown in FIG. The case C wall portion surrounded by the three points (in other words, the part where the inner thickness of the transmission case corner is the largest in the conventional configuration) can be omitted, making the wall thickness of the case corner smaller than the other case wall portions. It is possible to make the case thicker or the same thickness, and as a result, the occurrence of cracks during case casting can be suppressed, making case manufacturing much easier.

Next, embodiments of the present invention will be described in detail based on illustrative drawings.

As shown in FIG. 1, a front driving section 4, a passenger driving section 5, and a rear transmission section 6 are provided on a fuselage frame 3 equipped with a pair of left and right steering front wheels 1 and a pair of propulsion rear wheels 2. At the same time, a working machine such as a mowing machine 7 is attached to the lower part of the front and rear center of the machine body so as to be able to be raised and lowered to form a tractor.

When the transmission unit 6 is configured, as shown in Figs. 1 and 2, a hydraulic continuously variable transmission (HST) is configured to input the power from the driving unit 4 via a transmission shaft 8.
The driving section 5 is provided with a pedal 13 for changing the vane angle of a hydraulic pump P of the continuously variable transmission 9 to continuously change the vehicle speed and switch between forward and reverse travel. The three components are connected together in this order: a gear reduction device 10 for reducing the speed change power from a hydraulic motor M of the continuously variable transmission 9; and a differential device 12 having an axle 11 to which the rear wheels 2 are attached, the differential device 12 being provided with an axle 11 to which the rear wheels 2 are attached. The driving section 5 is provided with a pedal 13 for changing the vane angle of a hydraulic pump P of the continuously variable transmission 9 to continuously change the vehicle speed and switch between forward and reverse travel.

To explain in more detail the hydraulic oil supply structure for the continuously variable transmission 9, the hydraulic oil stored in the cast transmission case C housing the gear transmission 10 and the differential device 12 is supplied to the transmission shaft 8 by the pump. The charge pump P ₁ installed in the continuously variable transmission 9 in a state in which the oil is disposed in series with the transmission case C is taken out via the strainer 15 provided in the oil intake port 14 of the transmission case C and the external hydraulic hose 16, and the charge pump P ₁ The oil discharged from the transmission case C is transferred to an external pipe 18 to a filter unit 17 attached to the wall of the transmission case C.
After passing through the pumps P and 18b, the pump is supplied to a circulation circuit 19 extending between the pump P and the motor M in the continuously variable transmission 9.

To configure the mounting structure of the filter unit 17 to the transmission case C, as shown in FIGS. 2 and 3, one screw hole 20 is provided on the outer surface of one side wall at the corner of the transmission case C. By forming a groove 21 in an annular arrangement surrounding it, and screwing and communicating the filtered oil extraction tapping 17a as a second connection port at the center of the end face of the filter unit 17 with the screw hole 20, the annular groove 21 and the oil intake portion 17 as the first connection port of the filter unit 17.
Filter unit 1 is in oil-tight communication with b.
7 is installed. And a connection port 22a for the external piping 18a, 18b,
22b are respectively formed on the front side of the other side wall of the corner portion of the transmission case C, and have an "L" shape in plan view that communicates the screw hole 20 and the annular groove 21 with the connection ports 22a and 22b, respectively. Two oil passages 23a,
23b, the oil passage 23a that communicates with the oil intake portion 17b is placed within the wall thickness of the other side wall where the oil filter 17 is not mounted, and the oil passage 23b that communicates with the filtered oil removal tapping 17a is placed within the wall thickness of the other side wall where the oil filter 17 is not mounted. The filter 17 is installed within the wall thickness of the one side wall, and both oil passages 23 as described above are provided.
Due to the arrangement of a and 23b, the wall thickness of the case C at the portion where they are bored is made as small as possible to prevent cracks etc. during casting of the case C.

Note that the filtered oil passed through the filter unit 17 can be supplied to various hydraulic devices instead of the hydraulic continuously variable transmission device 9.

In addition, various structural changes can be made to the specific fixing structure of the filter unit 17 to the transmission case C and the specific communication connection structure between the filter unit 17 or the external piping 18a, 18b and both the drilled oil passages 23a, 23b. .

The present invention is directed to drive units with filters in various types of work vehicles such as agricultural and construction vehicles.
Note that although reference numerals are written in the claims section of the utility model registration for convenience of comparison with the drawings, the present invention is not limited to the structure of the attached drawings by such entry.

[Brief explanation of the drawing]

The drawings show an example of the drive unit of a working vehicle according to the present invention.
FIG. 1 is an overall side view of a working vehicle, FIG. 2 is a sectional plan view and hydraulic circuit diagram showing an oil filter mounting structure, and FIG. 3 is a sectional view taken along the line - in FIG. FIG. 4 is a diagram corresponding to FIG. 2 showing a conventional structure. 9... Drive device, 17... Oil filter,
17a, 17b... Connection port, 23a, 23b...
Oil passage, C...transmission case.

Claims (1)

[Claims for Utility Model Registration] 1. An annular first connection port 17 is provided on one of the outer surfaces of the corner portions of the cast transmission case C that are substantially perpendicular to each other.
b and a second connection port 17a surrounded by the first connection port 17b. L-shaped oil passages 23a and 23b are connected to the first connection port 17b and the second connection port 17a, respectively, within the thickness of the transmission case C, with both ends thereof being connected to the other side. In the driving part of the work vehicle, the oil passage 23a for the first connection port 17b is formed within the wall thickness along the other outer surface, and
A drive unit for a working vehicle, characterized in that an oil passage 23b for the work vehicle is formed within the wall thickness along the one outer surface. 2. The working vehicle according to claim 1, wherein the filter 17 cleans the oil flowing into the hydraulic drive device 9 that is integrally connected to the transmission case C. Drive part.