JPH0249053Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Industrial application field This invention is suitable for use in work vehicles, especially combine harvesters.
The present invention relates to an oil circulation device in which a transmission case and an oil tank are connected through a pipe, and more particularly to a breather device thereof.

(B) Prior art In general, work vehicles such as combine harvesters are equipped with a large number of hydraulic devices to operate the work equipment, but these hydraulic devices use oil stored in the transmission case as hydraulic oil. It is used as

(c) Problems that the invention aims to solve However, the amount of oil in the transmission case is small, and the temperature of the oil increases rapidly due to the agitation of the oil by the transmission and the operation of the hydraulic equipment. In addition to having an adverse effect on the oil, there is a risk that the oil will deteriorate more quickly and that maintenance will be hindered.

It is also conceivable to install a special oil tank for the hydraulic equipment, but in this case as well, the transmission case, which has a relatively small capacity, causes a rapid increase in oil pressure and requires special equipment such as an oil cooler.

On the other hand, the oil in the transmission case tends to reach high temperatures, so it is necessary to install a breather device to prevent the oil from becoming high-pressure. Therefore, if the breather device is directly installed in the case, oil will blow out from the breather pipe.

As a result, oil consumption increases, requiring frequent oil replenishment, and there is a risk that blown oil may be applied to the belt, causing problems such as belt slip.

(d) Means for solving the problem The present invention aims to solve the above-mentioned problems, and for example, as shown in Figure 1,
A work vehicle such as a combine harvester, in which a hydraulic pump 32 sucks oil in a transmission case 12a containing a power transmission device linked to a traveling device through a suction pipe 42, and discharges it toward hydraulic equipment 37, 35. At this point, an oil tank 15 is installed. Then, oil is discharged from the hydraulic equipment to the oil tank 15 via the return hose 45, and the oil tank 15 and the transmission case 12a are connected via the bypass pipe 47 below the oil level L. They communicate with each other through a flow pipe 50 above the oil level L. A breather device 55 including a breather pipe 52 and a breather tank 53 provided above the pipe 52 is disposed above the oil level L of the oil tank 15.

(E) Effect Based on the above configuration, most of the oil that passes through each hydraulic device 37 is discharged to the oil tank 15,
Furthermore, it is guided to the mission case 12a through the bypass pipe 47, and is sucked in by the hydraulic pump 32 again.

At this time, inside the mission case 12a,
Although the pressure tends to be high, the air above the flow pipe 50 communicates with the air above the oil tank 15, and further communicates with the atmosphere via a breather device 55 provided in the oil tank 15.
2a never becomes high pressure. Furthermore, although the air above the oil level L of the transmission case 12a is a spray-like atmosphere due to scattered oil, the spray-like oil turns into oil droplets and falls while communicating with the oil tank 15 through the float pipe 50. Above the oil level L in the tank 15, there is an air layer free from oil droplets, so that oil does not blow out from the breather device 55.

(F) Embodiments Hereinafter, embodiments in which the present invention is applied to a combine harvester will be described with reference to the drawings.

As shown in FIG. 2, the combine 1 has a body 3 supported by a crawler 2, and a driver's seat 5, a grain tank 6, and an engine 7 are arranged from the front on one side of the body. An automatic threshing machine 9 is installed at the other end. Furthermore, a pre-processing section 10 is supported at the front of the machine body 3 so as to be able to rise and fall freely, and a large number of dividers 11, a raking device, a cutting blade, a grain culm conveying device, etc. are arranged in the pre-processing section. . Further, a transmission case 12 and a counter case 13 are arranged inside the machine of the driver's seat 5, and an oil tank 15 is arranged inside the machine of the grain tank 6.
is located.

Further, as shown in FIG. 3, the mission case 12 includes a main case 12a and a sub case 12b.
The main case 12a includes a forward hydraulic clutch 16, a reverse hydraulic clutch 17, left and right side clutches 19l and 19r, and left and right brakes 20.
l, 20r, and left and right axles 21... are disposed, and the sub case 12b has an auxiliary transmission gear 22,
A pre-processing section transmission gear 23 is provided. Furthermore,
A sprocket 25 is fixed to each of the left and right axles 21 protruding from the main case 12a.
These sprockets 25 are engaged with the crawler 2. In addition, the shaft 2 protruding from the sub case 12b
A driven speed change pulley 29b equipped with a main clutch 27 is supported at 6, and a belt 3 is connected between the pulley 29 and a drive speed change pulley 29a mounted on a shaft 30 supported by the counter case 13.
1 is wound around to form a continuously variable transmission 29. In addition, the counter case 13 includes a hydraulic pump 3.
2 is installed, and the pump 32 is connected to the engine 7.
The continuously variable transmission 29
is driven together.

As shown in FIG. 1, the main transmission case 12a is disposed at the lower part of the fuselage at approximately the center in the left-right direction of the fuselage. The reverse hydraulic clutches 16 and 17 are filled with oil so as to partially cover them (see oil level L), and a valve device 35 for controlling these hydraulic clutches 16 and 17 is installed on the case 12a. There is. Further, the counter case 13 is arranged diagonally rearward and upward of the mission case 12, and further includes a valve unit 37 to which hydraulic pressure is supplied from a hydraulic pump 32 installed in the counter case 13 via a delivery pipe 36. driver's seat 5
It is arranged below the seat 5a. Further, the oil tank 15 is arranged between two square pipes forming the body frame, and a filter 41 is further installed above the oil tank 15 and below the hydraulic pump 35. A suction pipe 42 with a rubber pipe 42a interposed in the middle extends from the lower part of the main transmission case 12a, and further extends from the filter 41 with a rubber pipe 43 similarly in the middle.
The suction pipe 43 having a
It extends towards 2. Also, valve unit 3
7, a first return hose 45 extends toward the oil tank 15, and a second return hose 46 extends toward the valve device 35 and the main transmission case 12a. Further, the lower part of the oil level L of the oil tank 15 and the lower part of the oil level of the main transmission case 12a are communicated by a bypass pipe 47 having a rubber pipe 47a, and the bypass pipe 47 extends in parallel with the suction pipe 42. and is open adjacent to the case 12a.
Further, the upper surface 15a of the oil tank 15 and the upper part of the main transmission case 12, that is, the upper part of the oil level L, are communicated by a flow pipe 50, and the case 12a side of the flow pipe 50 is connected to a hydraulic clutch for forward and backward movement. The clutches 16, 17 are opened above so that the flow oil from the flow pipe 50 is applied to the clutches 16, 17.

Further, an oil filler port 57 is installed on the upper surface 15a of the oil tank 15, and a breather device 55 extends from the oil filler port 57. The breather device 55 includes a breather pipe 52 that is continuous with the fuel filler port 57 and extends upward.
The tip of the pipe 52 is connected to the bottom of a reserve tank 53 disposed above the counter 13, and a breather hose 54 whose tip is open to the atmosphere is connected to the top of the tank 53. In addition, Fig. 4 is a diagram showing a hydraulic circuit that operates each operating device of this combine. In the figure, 60 is a flow divider, and a small amount of oil flows into the constant pressure side oil passage a, and the hydraulic clutch 16, 17 Control valve device 3
5, a large amount of oil flows into the fluctuating pressure side oil path b, and a hydraulic device 61 for controlling the grain tank, a hydraulic device 62 for controlling the pre-processing section, a hydraulic device 63 for controlling the side clutch, and a continuously variable transmission control. hydraulic equipment 65 and hydraulic equipment 66 for controlling the handbrake.

Since this embodiment has the above-described configuration, rotation from the engine 7 is transmitted to the shaft 30 of the counter case 13, and further transmitted to the continuously variable transmission 29 and to the hydraulic pump 32. The rotation, which is appropriately changed in speed by the continuously variable transmission 29, is transmitted to the pre-processing section 10 via the gears 22 and 23 in the sub-case 12b, and is also transmitted to the forward clutch 16 in the main transmission case 12a. The forward rotation or reverse rotation based on the engagement of these clutches 16 or 17 is transmitted to the left and right axles 21 via the left and right side clutches 19l and 19r, or the left and right axles 21
Then, the combine harvester is steered by braking with the left and right brakes 20l and 20r.

On the other hand, the hydraulic pressure driven by the hydraulic pump 32 is supplied by a flow divider 60 to the valve device 35 of the hydraulic clutches 16 and 17 for forward and backward movement, and also to the hydraulic equipment 61 for controlling the grain tank and the hydraulic pressure for controlling the pre-processing section. equipment 62, side clutch control hydraulic equipment 63, continuously variable transmission control equipment 65, and side brake control hydraulic equipment 66, and based on appropriate control of these hydraulic equipment, forward clutch 16 and reverse clutch 17 are supplied. movement of the grain transfer cylinder of the grain tank 6, lifting and lowering of the pre-processing section 10, left and right side clutches 19l, 1
9r is engaged and disconnected, the continuously variable transmission 29 is operated to change gears, and the left and right side brakes 20l and 20r are operated while braking.

Based on the drive of the hydraulic pump 32, oil is sucked into the suction pipe 42 from the lower part of the main transmission case 12a, and further into the pump 32 through the filter 41 and the second suction pipe 43. The oil discharged from the pump 32 is sent to the valve unit 37 via the delivery pipe 36, sent to each hydraulic device by the flow divider 60 in the valve unit 37, and then the oil in the flow divider 60 is sent to the valve unit 37. A large flow of oil based on path b is returned to the return hose 45.
is discharged to the oil tank 15 via
A small flow of oil based on the oil path a is sent to the forward/reverse valve device 35 via the second return hose 46 and is discharged into the main case 12a. At this time, for example, when the hydraulic pump 32 discharges 15 oils per minute, 12 oils are discharged to the first return hose 45 and 3 oils are discharged to the second return hose 46. From the oil tank 15, 13
of oil will be returned.

The bypass pipe 47 and the suction pipe 42 are open adjacent to the main transmission case 12a, and therefore the suction pipe 42
Almost all of the oil (12) is sucked into the suction pipe 42, increasing the proportion of clean oil from the oil tank 15 in the oil sent to each hydraulic device, and the remaining amount (3) is sucked into the suction pipe 42 from the main case 12a. The main case 12a is
The oil is circulated to prevent it from getting too hot.

Note that, in reality, the entire amount from the return hose 45 does not flow into the bypass pipe 47;
The amount of suction from the main case 12a will inevitably be large, and the amount of discharge from the return hose 45 will also vary depending on the usage status of the hydraulic equipment.
The oil tank 15 tends to become full. Therefore, when the oil tank 15 becomes full, oil flows from the oil tank 15 to the main case 12a through the flow pipe 50. The flow oil then flows over the forward and reverse hydraulic clutches 16 and 17 to lubricate them.

On the other hand, the oil is cooled while circulating through the oil tank 15 and each pipe and hose, but the oil in the main transmission case 12a is agitated by gears, clutches, etc. and tends to reach a high temperature.
In this case, the pressurized air in the case 12a is guided above the oil level L of the oil tank 15 through the flow pipe 50. Furthermore, it is released into the atmosphere from the breather pipe 52, reserve tank 53, and breather hose 54. At this time, the atmosphere above the transmission case 12a is agitated by the hydraulic clutches 16, 17, etc., and oil is scattered in the form of a spray. The remaining oil droplets are further absorbed by the oil in the oil tank 15 at the upper part of the oil tank 15, and almost only air is led out to the breather pipe 52. Furthermore, even if the oil tank 15 also becomes high pressure and oil is pumped up into the breather pipe 52, the blown oil will only be blown out into the reserve tank 53, and the blown oil will be stored in the reserve tank and will not leak from the breather hose 54. . The oil in the reserve tank 53 is returned to the oil tank 15 when the pressure in the oil tank 15 is released due to engine stop or the like.

(g) Effect of the invention As explained above, according to the invention, the oil tank 15 is provided, oil from the hydraulic equipment is discharged to the oil tank, and the oil tank and the transmission case 12a are bypassed. pipe 4
4, the oil circulates between the oil tank 15 and the transmission case 12a, preventing the temperature from rising excessively, and preventing the oil from deteriorating early. Oil tank 15 above oil level L
and the transmission case 12a and the flow pipe 50.
Since the breather device 55 is arranged above the oil level of the oil tank 15, one breather device 55 can serve as both the transmission case 12a and the oil tank 15.
Further, oil droplets from the mission case 12a become oil droplets in the flow pipe 50 and the oil tank 15 and are absorbed by the oil, thereby preventing oil from blowing out from the breather device 55. This reduces oil consumption and facilitates maintenance, and also prevents leaking oil from being removed from the belt.
It is possible to prevent problems such as belt slip by preventing adhesion to the belt.

Furthermore, by interposing the reverse tank 53 in the breather device 55, oil blow-out can be more reliably prevented.

[Brief explanation of the drawing]

Fig. 1 is a side view showing an oil circulation device according to the present invention, Fig. 2 is a side view showing a combine harvester to which the present invention is applied, Fig. 3 is an expanded sectional view showing the power transmission device, and Fig. 4 is a side view showing an oil circulation device according to the present invention. It is a diagram showing the hydraulic circuit. 1... Work vehicle (combine harvester), 2... Travel device (crawler), 3... Airframe, 12... Mission case, 12a... Main case, 12b...
Sub case, 13... Counter case, 15...
Oil tank, 32... Hydraulic pump, 35, 37
...Hydraulic equipment (valve units, valve devices),
36...Delivery pipe, 41...Filter, 4
2, 43... Suction pipe, 45, 46...
Return hose, 47... Bypass pipe, 50
... Flow pipe, 52 ... Breather pipe, 5
3... Reserve tank, 54... Breather hose, 55... Breather device, 57... Fuel filler port.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A transmission case containing a built-in power transmission device linked to a traveling device, a hydraulic pump and hydraulic devices for operating and operating various operating devices, and the hydraulic pump is connected via a suction pipe. In a work vehicle that sucks oil in a transmission case and discharges it toward a hydraulic device, an oil tank is provided to conduct the oil from the hydraulic device through a return hose, and the oil tank and the transmission case are connected to each other. the system case is in communication with the oil tank below the oil level via a bypass pipe and above the oil level with a flow pipe, and the breather device is in communication with the oil tank above the oil level. An oil circulation device for a work vehicle characterized by: (2) The oil circulation system for a work vehicle according to claim 1, wherein the breather device comprises a breather pipe and a reserve tank provided above the breather pipe.