JPH022187Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention is a general type combine harvester, in other words, the planted grain culm is collected by a reel and harvested by a cutter bar, and the harvested grain culm is transferred to the cylinder of the threshing section by the action of an auger and a feeder conveyor. This is a type of combine harvester that guides the grain to grains, threshes the grain through the cooperative action of the cylinder and beater, and obtains fine grain through sorting.The combine harvester is equipped with the above-mentioned cutter bar, auger, feeder conveyor, etc., and is capable of vertically moving the above-mentioned reel. The present invention relates to a reaping table elevating device for raising and lowering a reaping table (also referred to as a "table" or "platform") that is supported and movably supported at the front of a machine body.

Conventional technology As is well known, in a conventional combine harvester, the reaping table, which is supported in the front part of the machine so that it can be raised and lowered, is raised and lowered by a single-acting hydraulic cylinder. Conventionally, directional control valves for
4326987, or a manual lever and a sensor for detecting the ground height of the cutting table as disclosed in Japanese Patent Publication No. 47-34609. Electromagnetic valves designed to obtain a uniform positional displacement are known.

Problems to be solved by the invention If we compare the above-mentioned former structure with a valve and the latter structure with a valve, at first glance it seems that the latter structure can automatically adjust the cutting height. Although this is considered advantageous in that it automatically avoids the situation where the reaping table runs into a convex portion on the field, there are actually various problems.

In other words, the reaping platform can be maintained at a constant height by placing the directional control valve in the neutral position.
In the above-mentioned Japanese Patent Publication No. 47-34609, the electromagnetic directional valve is associated with a sensor and a manual lever, so the manual lever can switch the electric circuit to move the directional valve to the ascending position or the descending position. After moving the reaping table to the position and raising or lowering the reaping table, the directional control valve is kept in the neutral position regardless of the sensor signal so as to hold the reaping table in that position by turning off the power switch. It is said that

Therefore, in order to move the machine around in the field or cross over ridges, it is necessary to raise the reaping table by operating a lever and simultaneously turn off the power switch. When going over a ridge, the power switch must be turned off even if the manual lifting of the reaping table is insufficient and the reaping table pushes into the ridge, causing damage to the cutter bar, etc. Therefore, it becomes impossible to deal with such an emergency situation only by operating the lever.
To manually control the cutting height,
A troublesome situation arises in which the user must constantly operate the lever and the power switch, or must constantly hold the lever.

By the way, the standard type combine harvester is a self-propelled combine that transports the grain culm in an orderly manner through the feed chain on the side of the threshing section, inserts only the tip of the grain into the handling chamber, and threshes the grain with the handling barrel. While it is required not to disturb the orderliness of grain culms during transportation, since the entire harvested grain culm is fed to a cylinder for threshing, the cutting height can be strictly controlled. There is no requirement to maintain the orderliness of the culm.

Therefore, the special public corporation Sho, which has the above-mentioned problems,
The simple type disclosed in U.S. Patent No. 4326987 mentioned above is better than the one disclosed in U.S. Patent No. 47-34609. Situations that result in damage to equipment must be avoided.

This invention attempts to solve such problems and ensure safety.

Technical measures taken to solve the problem The reaping platform elevating device for an ordinary type combine harvester of this invention, which was developed under the purpose of this invention, uses a hydraulic pump 1 to supply hydraulic oil, as illustrated in FIG. In the main circuit 2 to be supplied, a directional switching valve 5 is connected to a hydraulic cylinder 3 for raising and lowering the reaping table via an oil supply/discharge circuit 4 and controls the supply/discharge of hydraulic oil to the hydraulic cylinder 3; A solenoid valve 6 having a first position for maintaining the main circuit 2 in a conductive state and a second position for connecting the main circuit 2 to the hydraulic cylinder 3 is connected in series with each other and inserted. The valve 6 is connected to the hydraulic cylinder 3 via an oil supply circuit 8 into which a check valve 7 that allows oil to flow only in the direction of the hydraulic cylinder 3 is inserted, and the reaping table 9 (see Fig. 2-4) is connected to the field area. ) is provided, and the sensor 10 (FIG. 2) detects the lower limit height, and the detection operation of this sensor 10 causes the solenoid valve 6 to be
It is configured to be displaced to the position of.

Operation When the reaping table 9 at the front of the machine encounters a convex part on the field surface during harvesting work in the field and becomes relatively lower than the lower limit height set in the sensor 10, the detection operation of the sensor 10 is activated. Since the solenoid valve 6 is displaced to the second position, the main circuit 2
Hydraulic oil is supplied from the oil supply circuit 8 to the hydraulic cylinder 3, and the hydraulic cylinder 3 extends and lifts the reaping table 9, so that the reaping table 9 or the cutter bar 12 at its lower end plunges into the convex part. damage is prevented. Even if the amount of rise of the reaping table 9, which has been raised by moving the directional control valve 5 to the raising action position U when crossing the ridge, is insufficient,
Since the sensor 10 performs a detection operation in response to the insufficient lifting amount and the reaping table 9 is lifted, safety is also ensured.

In the illustrated example, according to an embodiment of the invention, a throttle 1 is provided in the oil supply circuit 8 and connected in series with the check valve 7.
1 is inserted, and this restrictor 11 makes the raising speed of the reaping table smaller when the reaping table is raised by the solenoid valve 6 than when the reaping table is raised by the switching valve 5, and the solenoid that may occur unexpectedly by the operator is This is intended to alleviate the shock when the reaping table is raised by the valve 6 and to avoid excessive lifting of the reaping table 9 when the sensor 10 is activated.

Embodiment Figures 3 and 4 show a conventional combine harvester equipped with an embodiment of the invention.

As usual, the reaping table 9 of the combine is supported so as to be rotatable up and down on the front part of the machine body which is moved by crawlers 14, and is raised and lowered by the hydraulic cylinder 3 disposed between the machine body and the machine body. It will be done.

The reaping table 9 has dividers 15 on both sides, a cutter bar 12 at the lower end, an auger 16 located behind the cutter bar 12 and which collects the reaped grain culm at one point in the width direction of the reaping table. It is equipped with a feeder conveyor 17 etc. that conveys the grain in an upward diagonal direction, and also supports a reel 18 for raking up the planted grain culm so that it can be raised and lowered.
In the illustrated combine harvester, the reel frame 18a is configured to be extendable and retractable, and the reel 18 is raised and lowered by a pair of left and right reel lift cylinders 19, and the base end and tip end of the reel frame 18a are extendable and retractable. The reel is moved forward and backward by a pair of left and right reel forward and backward movement cylinders 20 disposed between the two parts.

The aircraft, which has a pilot's seat 21 installed on one side of the front part, has a threshing section equipped with a cylinder 22 to which grain culm is supplied by the feeder conveyor 17, and the threshed grain is sorted by the cylinder 22. A sorting section equipped with an oscillating sorting device 23 is provided. The grains carefully selected in the sorting section are stored in a grain tank 24 inside the machine body, and a grain lifting cylinder 25 is provided in communication with the lower part of the grain tank 24 and housing an auger therein. Similarly, the first and second grain delivery tubes 26 and 27 are equipped with an auger.
is installed on one side of the upper surface of the machine, and among these, the first grain delivery cylinder 26 is supported at the upper end of the grain lifting cylinder 25 so as to be movable up and down about the horizontal axis X shown in FIG. It is communicated with the inside of the grain frying cylinder 25. Further, the second grain delivery tube 27 is placed at the tip of the first grain delivery tube 26 in a folded position in which it is folded along the first grain delivery tube 26 as shown in FIG. It is rotatably supported in an extended position in which it is rotated from the center and positioned on an extension line of the first grain delivery tube 26 and communicated with the first grain delivery tube 26. The grain lifting tube 25, which supports the grain discharge tubes 26, 27 on the upper end side, is rotatably supported around its axis, and when rotated, the grain discharge tubes 26, 27
7 will be rotated horizontally.

To transfer grain from the grain tank 24 of the aircraft to a truck or the like, move the second grain delivery cylinder 27 to the above-mentioned extended position, and rotate the grain lifting cylinder 25 to properly move the grain delivery cylinders 26, 27. swivel to the first position and
The second grain discharging cylinder 27 and the second grain discharging cylinder 27 are rotated upward by an appropriate angle. In order to rotate the grain lifting cylinder 25, the unloading cylinder rotating cylinder 28 shown in FIG.
In order to raise and rotate the cylinders, a lift cylinder 29 shown in FIG. 3 is provided. In order to rotate the second grain delivery cylinder 27, a mechanical operating mechanism 30 with an operating end facing the vicinity of the cockpit 21 is provided. In FIG. 3, S is a support fixed to the upper surface of the machine body to receive and support the grain delivery tube 26 in the lowered position shown in the figure.

FIG. 1 also shows a circuit diagram of a hydraulic pressure supply device installed in the illustrated combine harvester.

The main circuit 2, which is supplied with hydraulic oil from an oil tank 31 by the action of a hydraulic pump 1, is connected to the reel/lift cylinder 19 via an oil supply/discharge circuit 31 to supply and discharge hydraulic oil to the cylinder 19. The directional switching valve 32 to be switched and controlled and the directional switching valve 5 are inserted and installed in this order. These directional switching valves 32, 5 sandwich the neutral position N, and the reel 18 is placed in a rising operation position U where each cylinder 19, 3 is extended by supplying hydraulic oil and allows oil drain from each cylinder 19, 3. The reaping table 9 has a lowering operation position D in which the reaping table 9 lowers while contracting the cylinders 19 and 3 due to its own weight. Note that for the reel/lift cylinder 19 on one side, as shown in the figure, the reel/lift cylinder 19 on the other side is
Hydraulic oil is supplied from the oil chamber on the extension end side of the cylinder 19 in order to obtain complete synchronized expansion and contraction of both the left and right cylinders 19.

The pump port of each directional valve 32, 5 is connected to the main circuit 2 via a respective separate check valve 33, 34, and when both directional valves 32, 5 are in the neutral position N, the pump port is connected to the main circuit 2. 2 in a conductive state. The solenoid valve 6 is inserted into the main circuit 2 on the downstream side of the directional control valves 32 and 5, and the main circuit 2 is further connected to the flow divider 35 via the solenoid valve 6.

The flow divider 35 maintains a constant flow rate by inserting a variable throttle 36 on the main circuit 2 side and a relief valve 37 on the branch circuit side that allows the hydraulic pressure on the secondary side of the throttle 36 to act as pilot pressure from the valve spring direction. A regulating flow circuit 38 on the secondary side of the throttle 36 that maintains a constant flow rate is
The oil supply circuit for the cylinders 20, 28, and 29 is configured. That is, the regulating flow circuit 38 is sequentially
It is connected to a directional switching valve 39 for the reel longitudinal movement cylinder 20, a directional switching valve 40 for the unloading tube rotation cylinder 28, and a directional switching valve 41 for the unloading tube lift cylinder 39 on the primary side of each switching valve. .

The directional control valve 39 has a pair of oil supply and discharge circuits 42 and 43.
The extension oil chamber 20a of the reel longitudinal movement cylinder 20 on one side and the reel longitudinal movement cylinder 20 on the other side
The contraction oil chamber 20b of the former cylinder 20 and the expansion oil chamber 20a of the latter cylinder 20 are connected by a circuit 44. The directional control valve 40 has a pair of oil supply/discharge circuits 45 and 46, and is connected to an extension oil chamber 28a and a contraction oil chamber 28b of the delivery tube rotation cylinder 28.
and is connected to. The directional switching valve 41 is a single-acting type lift cylinder 29 because the grain unloading cylinders 26 and 27 can be lowered by their own weight.
, and is connected by an oil supply/drainage circuit 47.
As shown in the figure, each of these directional switching valves 39, 40, and 41 has a neutral position in between, and an operating position in which the cylinder whose operation is to be controlled is extended and contracted.

In the oil supply/drainage circuit 4 between the directional control valve 5 and the hydraulic cylinder 3, there is a check valve 49 that prevents oil from being discharged from the hydraulic cylinder 3 at the neutral position N of the directional control valve 5.
and a slow return valve 50, which is formed by connecting a check valve 50a and a throttle 50b in parallel, which allow oil to flow only in the three directions of the hydraulic cylinder, are installed, and the slow return valve 50 is inserted and installed, and the slow return valve 50 is inserted in Said oil supply circuit 8
In the illustrated case, the check valve 49 and the slow return valve 50 are connected to the oil supply/drainage circuit 4, thereby being connected to the hydraulic cylinder 3. Check valve 4 mentioned above
9 is opened by the hydraulic pressure applied via the circuit 51 from the hydraulic port provided on the secondary side of the directional switching valve 5 when the directional switching valve 5 is moved to the downward operating position D, and the oil from the hydraulic cylinder 3 is released. It is assumed that emissions are allowed. That is, as shown in FIG. 5, the check valve 49 is disposed between an oil passage 52 connected to the cylinder port of the switching valve 5 and an oil passage 53 led in the direction of the slow return valve 50 shown in FIG. The oil passage 52 is seated on the valve seat 55 by the force of the valve spring 54 and the hydraulic pressure applied from the hydraulic cylinder 3 side.
Although it is supposed to cut off communication between oil passages 53 and 53,
A piston 5 located opposite the check valve 49 on the 2 side.
6, and an operating rod 56a for pushing the check valve 49 to open it is attached to the piston 56. Behind the piston 56 is a circuit 5 shown in FIG.
When hydraulic pressure is applied to this oil passage 57, the piston 56 moves forward and the operating rod 56a pushes the check valve 49 open.

Similar check valves 59 and 60 are also inserted in the oil supply/discharge circuit 31 between the directional switching valve 32 and the reel/lift cylinder 19 and the oil supply/discharge circuit 47 between the directional switching valve 41 and the unloading cylinder lift cylinder 29. Further, apertures 61 and 62 are also inserted into each of these circuits 31 and 47.

Each oil supply/discharge circuit 42, 43 between the directional switching valve 39 and the reel longitudinally moving cylinder 20, and each oil supply/discharge circuit 45 between the directional switching valve 40 and the delivery tube rotating cylinder 28,
46 are respectively inserted with check valves 63, 64, 65, 66 that prevent oil leakage from each cylinder 20, 28 when the switching valves 39, 40 are at their neutral positions as shown in the figure. Each of these check valves 63-66 controls the hydraulic pressure when the hydraulic pressure is established in the circuit that is paired with the circuit 42, 43, 45, 46 in which it is inserted (for example, circuit 43 in case of circuit 42). It is said to be opened by pilot. Such a check valve is already known as disclosed in, for example, Japanese Utility Model Application Publication No. 59-195204, and the check valve 4 shown in FIG.
The opening mechanism is similar to that of No. 9. The oil supply and drain circuits 45 and 46 have a throttle 67,
68 is also inserted.

As shown in FIG. 1, the directional switching valves 32, 5 are integrated into a valve unit 70, and the valves between the switching valves 32, 5 and the cylinders 3, 19, the solenoid valve 6, and the valves attached thereto are integrated into the valve unit. 71, and the directional control valve 3
9, 40, 41 and cylinders 20, 28,
The valves between 29 and 29 are combined into a valve unit 72. A relief valve 73 for setting the hydraulic pressure applied to the cylinders 19, 3 is provided in the valve unit 70.
Overload relief valves 74 and 75 for preventing excessive hydraulic action on valve unit 71
It is provided in A relief valve 76 for setting the hydraulic pressure applied to the cylinders 20, 28, 29 is provided in the valve unit 72.

FIG. 2 shows the specific structure of the sensor 10.

The sensor 10 includes a sled 79 that is rotatably supported around a horizontal fulcrum shaft 78 immediately behind the cutter bar 12 and has a width spanning the entire width of the lower surface of the cutter bar 12. A switch 81 is fixedly arranged on a support frame 80 provided at an upper position within the reaping table 9, and a switch plate 82 for turning on the switch 81 is mounted within the support frame 80 around a horizontal support shaft 83. It is rotatably provided. The sled 79 and the switch plate 82 are connected by a rod 86 between the respective sensor members 79, 82 and the arms 84, 85 that rotate integrally, so that the sled 79 is connected as shown by the solid line in FIG. When the switch plate 82 climbs onto the convex part of the ground at the set height, the switch 8
They are interlocked and connected so that they can be rotated to the position where the switch 1 is turned on. 86' in Figure 2
is a stopper rubber that restricts the amount of displacement of the switch plate 82 in the switch-off direction.

The switch 81 is inserted into a circuit that connects the solenoid of the electromagnetic valve 6 to a power source (not shown).

During harvesting using the illustrated regular combine harvester, the position of the reel 18 is adjusted according to the state of the planted grain culms in the field. That is, normally, the reel/lift cylinder 19 is expanded or contracted by operating the directional control valve 32, and the lower surface of the reel 18 is adjusted to be located approximately at the upper end of the planted grain culm. By operating the directional control valve 32, the reel
The lift cylinder 19 is contracted to lower the position of the reel 18, and the reel forward and backward movement cylinder 20 is extended by operating the directional control valve 39 to move the reel 18 forward, so that the reel 18 acts quickly on the lodging grain culm. Improves the raking of the grain culm.

Adjustment of the cutting height during harvesting work, which is carried out while the machine is traveling on the crawler 14 in the field, is carried out by operating the directional control valve 5 to extend and retract the hydraulic cylinder 3 for raising and lowering the reaping table, and raising and lowering the reaping table 9. It can be done. As described above, the electromagnetic valve 6 ensures safety during such work and when the reaping table 9 is raised to cross the ridge.

When transferring grains from the grain tank 24 inside the machine to a truck or the like, the second grain carrying tube 27 is extended as described above by the operation mechanism 30, and the grains are carried out by operating the directional control valves 40, 41. The cylinder turning cylinder 28 and the lifting cylinder 29 are extended, and the grain carrying cylinders 26 and 27 are moved to an appropriate position in which they are rotated horizontally and upwardly as described above.

The flow divider 35 shown in FIG. 1 allows a constant flow of oil to flow into the regulating flow circuit 38 regardless of the rotational speed of the pump 1, thereby keeping the operating speeds of the cylinders 20, 28, 29 constant. 3
In step 5, if only a part of the pump discharge oil amount is supplied to the three types of cylinders 20, 28, and 29 that do not require quick operation, the pipe line after the flow divider 35 may be The drop in hydraulic pressure inside the pump is reduced, and the horsepower loss of the hydraulic pump 1 is reduced. Conversely, hydraulic cylinder 3 for raising and lowering the reaping table
Depending on the circuit structure in which the entire amount of pump discharge oil is supplied to the reel lift cylinder 19 and the reel/lift cylinder 19, a quick response is required depending on the condition of the planted grain culm during harvesting work. The reaping table 9 can be raised and lowered and the reel 18 can be raised and lowered appropriately.

Effects of the invention This invention provides a solenoid valve 6 in the main circuit 2 that receives hydraulic oil from the hydraulic pump 1, in addition to the directional control valve 5 that controls the operation of the hydraulic cylinder 3 for raising and lowering the reaping table of an ordinary combine harvester. A sensor 10 is inserted together with the directional control valve 5 and detects the lower limit height of the reaping table 9.
By the detection operation, the main circuit 2 is connected to the hydraulic cylinder 3 by the electromagnetic valve 6, and the reaping table 9 is automatically raised when a condition such as a cutter bar at the lower part of the reaping table protrudes into a convex part on the ground occurs. Therefore, safety is automatically ensured with the directional control valve 5 kept in the neutral position, and desired safety is ensured both during harvesting work and when crossing ridges.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing a hydraulic pressure supply system installed in an ordinary type combine harvester equipped with an embodiment of this invention, Fig. 2 is a longitudinal side view showing a part of the combine harvester, Figs. 3 and 4. 5 is a schematic side view and a plan view of the combine, respectively, and FIG. 5 is a sectional view showing a specific structure of a part of the hydraulic circuit shown in FIG. 1. 1...Hydraulic pump, 2...Main circuit, 3...Hydraulic cylinder for lifting and lowering the reaping table, 4...Oil supply and drainage circuit, 5...
... Directional switching valve, 6 ... Solenoid valve, 7 ... Check valve, 8
...Oil supply circuit, 10...Sensor, 11...Aperture, 79...Warp, 81...Switch.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A main circuit 2 supplied with hydraulic oil by a hydraulic pump 1, which is connected to a hydraulic cylinder 3 for raising and lowering the reaping table via an oil supply/discharge circuit 4. has a first position where the main circuit 2 is maintained in a conductive state with the directional switching valve 5 that switches and controls the supply and discharge of hydraulic oil to the hydraulic cylinder 3, and a second position where the main circuit 2 can be connected to the hydraulic cylinder 3. The electromagnetic valve 6 is connected to the hydraulic cylinder 3 through an oil supply circuit 8 in which a check valve 7 is inserted which allows oil to flow only in the direction of the hydraulic cylinder 3. A sensor 10 for detecting the lower limit height of the reaping table 9 with respect to the field is provided.
A reaping table elevating device for a normal type combine harvester, wherein the solenoid valve 6 is displaced to the second position by the detection operation. 2. The reaping table elevating device for an ordinary type combine harvester according to claim 1, wherein a throttle 11 connected in series with the check valve 7 is inserted in the oil supply circuit 8.