JPH051230Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a lifting hydraulic cylinder for driving and lowering the reaping pre-processing section for this machine, such as a full-culm input type combine harvester, and the lifting hydraulic cylinder. The present invention relates to an elevating device for a reaping pre-processing section of a reaping harvester, in which a hydraulic circuit is provided with a switching valve that switches an oil path in order to supply or discharge hydraulic oil for elevating operation to a cylinder.

[Conventional technology]

Conventionally, as a lifting device for the pre-harvesting section in this type of reaping/harvesting machine, for example,
However, with this structure, the internal pressure of the lifting hydraulic cylinder decreases due to oil leakage from the oil passage, etc., and the reaping pretreatment section naturally descends. Therefore, as a solution to this problem, the following configuration has been proposed.

That is, by connecting an accumulator to a midway point in the hydraulic circuit that connects the lifting hydraulic cylinder and the switching valve that operates the lifting hydraulic cylinder, and floatingly supporting the reaping pretreatment section with the accumulation force of the accumulator, The structure is such that leaked oil is replenished into the lifting hydraulic cylinder by the internal pressure of the accumulator.

[Problem that the invention attempts to solve]

By the way, even in the case of a conventional structure equipped with an accumulator as described above, when the pressure oil accumulated in the accumulator decreases, it is necessary to immediately replenish the pressure oil. In the past, the switching valve was operated either manually or based on a detection result from a pressure detector installed in the accumulator that the pressure had dropped below a set pressure.

Therefore, when replenishing pressure oil by manually operating the switching valve during floating work with the pre-harvesting treatment section set as low as possible, if the timing of the operation is delayed, the pre-harvesting treatment section may plunge into the soil. If the operation time is too long, the reaping pre-processing section may be moved upwards unnecessarily, resulting in a decrease in work efficiency. If the valve is operated, pressure oil will not be replenished unless the pressure in the accumulator falls below the set pressure, so the reaping pre-treatment section will drop due to the pressure oil leak, causing the pressure to fall below the set pressure. There is a risk that it will fall into the soil before it reaches the ground level.

Furthermore, if the pressure inside the accumulator is not sufficient (too low), the accumulator must be filled with oil first before the lifting hydraulic cylinder is raised when the automatic lifting operation is performed, resulting in poor responsiveness. It also had some drawbacks.

The present invention has been developed in view of the above-mentioned circumstances, and is designed to maintain the pressure inside the accumulator at a state where the lifting cylinder can be supported in a floating state at all times. The purpose is to provide a processing unit elevating device.

[Means for solving problems]

In order to achieve the above object, the reaping pre-processing part elevating device in the reaping and harvesting machine according to the present invention has the above-mentioned structure, in which the elevating hydraulic cylinder and the switching valve in the hydraulic circuit are connected to each other. An accumulator is connected and arranged in the oil path between the two in a communicating state, and a height above the ground detecting device is provided in the pre-reaping treatment section, and the height above the ground of the pre-reaping processing section as determined by the height above the ground detecting device is below a set height. A pressure oil replenishment mechanism that replenishes pressure oil to the accumulator by intermittently switching the switching valve to the upward state based on the detection result that the height of the reaping pretreatment section The present invention is characterized by further comprising a mechanism for switching the switching valve to a lowered state for a set time based on a detection result that the above has occurred.

The functions and effects of this characteristic configuration are as follows.

[Effect]

When it is detected that the height of the reaping pre-treatment section above the ground has fallen below the set height, the switching valve is intermittently switched to the rising state, and the hydraulic pressure in the hydraulic circuit to which the accumulator is connected increases. Pressure oil is replenished into the accumulator.

When the cycle of intermittently switching the switching valve to the rising state is shorter than the time during which the switching valve is switched to the rising state, the switching valve is switched to the rising state before the pressure drops to the level before the switching valve is intermittently switched to the rising state. When the highest pressure in the hydraulic circuit gradually increases and exceeds the pressure required to drive and raise the pre-reaping section, the pre-reaping section will rise, but the amount of rise at this time is relatively small, and the When the height of the pre-treatment section above the ground exceeds the set height, the switching operation of the switching valve to the up state intermittently stops, the switching valve switches to the down state for a set short period of time, and the pre-reaping section moves back to the set height. When it is detected that the height above the ground is lower than the set height, the switching valve 11 is intermittently switched to the raised state again to replenish the accumulator with pressure oil.

[Effect of idea]

The accumulation pressure of the accumulator required for floating work is always ensured to prevent damage to the pre-reaping treatment section, and the height of the pre-reaping treatment section from the ground is adjusted to the set height based on the operation of the mechanism that replenishes pressure oil to the accumulator. When the height above the ground is exceeded, it is immediately lowered to close to the set height above the ground, allowing highly accurate floating work to be carried out efficiently.
Since the internal pressure of the accumulator is maintained almost constant at all times, the lifting operation can be performed efficiently with little time delay required for supplying pressure oil to the accumulator, and a decrease in responsiveness due to oil leaks can be suppressed. Summer.

〔Example〕

Hereinafter, embodiments of the present invention will be described based on the drawings.

As shown in FIG. 3, a reel 3 for raking the planted grain culms toward the rear of the machine, and a reaping device 4 for reaping the raked grain culms are attached to the front part of the machine frame 2 equipped with the crawler traveling device 1. , an auger 5 that receives the harvested grain culm, collects it in the center of the width of the machine, and sends it out to the rear; and a conveyor 6 that conveys the harvested grain culm to the rear of the machine with the ears in front. In addition to being provided with a drive that can be raised and lowered freely, a device 7 for threshing the harvested grain culms supplied from the pre-harvesting processing section A, and a tank 8 for collecting the grains after the threshing process are installed on the upper part of the body frame 2. This is a full-culm input type combine harvester, which is an example of a reaping harvester.

As shown in FIG. 1, the drive elevating mechanism of the reaping pre-processing section A comprises a lifting hydraulic cylinder 10 interposed between the support frame 9 of the reaping pre-processing section A and the machine frame 2; This hydraulic cylinder 10
An accumulator 12 is connected via an on-off valve 28 to a midway point in a hydraulic circuit 26 that connects the neutral return type three-position switching valve 11 that operates the switching valve 11 to an L-shaped link 13 and a rod 1.
4, and when the manual lever 15 is swung to the raised position U, the switching valve 1 is
1 switches to the raised state and the reaping pre-processing section A rises and swings to the neutral position N. When the reaping pre-processing section A stops moving up and down and is held at that position, the reaping pre-processing section A switches to the neutral state where it is held in the lowered position D. When the pre-reaping treatment section A is swung to the lower position, the reaping pre-processing section A is lowered. That is, when the switching valve 11 is switched to the upward state, hydraulic oil is supplied to the hydraulic circuit 26 to extend the hydraulic cylinder 10, and pressure oil is also supplied to the accumulator 12, causing the switching valve 11 to extend.
When the switching valve 11 switches to a neutral state, the hydraulic cylinder 10 is held in a constant state, and when the switching valve 11 switches to a lowered state, the hydraulic cylinder 10 is shortened by the load of the reaping pretreatment section A, and the hydraulic oil is transferred to the hydraulic circuit. 2
It is designed to be discharged from 6.

The L-shaped link 13, which is pivotally connected to the switching valve 11, is pivotally connected to a rising solenoid 16 that switches the switching valve 11 from the neutral state to a rising state, and a descending solenoid 17 that switches the switching valve 11 from the neutral state to a descending state. It is connected.

Next, the mechanism 18 for replenishing pressure oil to the accumulator 12 will be explained. The mechanism 18 for replenishing pressure oil to the accumulator 12 will be explained below. The front end of the sled body 19 is attached to swing freely in the vertical direction as the cutting height changes, and a link 20 is pivotally connected to the rear end of the sled body 19 and the support frame 9.
One end of the link 20 is pivotally connected via a rod 21, and a spring 22 is interposed between the other end of the link 20 and the support frame 9 to bias the sled body 19 in the direction of contact with the ground. A limit switch 23 is provided which detects when the body 19 is displaced upward and the height above the ground of the reaping pre-processing section A becomes lower than the set height by contact with the link 20. The height above the ground detecting device 24 of the pre-processing section A is configured.

A device 25 for exciting the solenoids 16 and 17 based on the operation of the limit switch 23 is provided, so that when the limit switch 23 is turned on, as shown in FIG.
As shown in FIG. 2B, the solenoid excitation device 25 with a built-in timer
is energized for a set period t at a set period T, and when the rising solenoid 16 is energized for a time t, the switching valve 11 is switched to the rising state during that time, and the oil pressure in the hydraulic circuit 26 is changed to d as shown in FIG. As shown, the pressure rises from the pressure P ₀ before the switching operation to the pressure P 1 which is lower than the pressure P ₂ required to drive and raise the reaping pre-treatment section A, the accumulator ₁₂ is replenished with pressure oil, and the raising solenoid 16 is demagnetized and the switching valve 11 returns to the neutral state, the oil pressure decreases due to pressure oil leak, and the limit switch 23 turns ON.
As the operation continues, the oil pressure repeats intermittently rising and falling at a cycle T, and the accumulator 12 is intermittently replenished with the pressure oil necessary for the floating operation.

At this time, if the period T is shorter than the excitation time t and the switching valve 11 is switched to the rising state again before the pressure P ₀ has fallen to the original pressure before the switching operation, the switching operation time t Since the maximum pressure in the hydraulic circuit 26 is constant, the accumulator 12 is replenished with pressure oil while the maximum pressure in the hydraulic circuit 26 gradually increases.

Next, a mechanism 27 that switches the switching valve 11 to the lowering state for a short time based on the detection result that the height above the ground of the reaping pre-processing section A has become equal to or higher than the set height.
To explain this, when the pre-reaping treatment section A exceeds the set height, the limit switch 23 is activated.
Based on this OFF operation, the intermittent excitation of the ascending solenoid 16 by the solenoid excitation device 25 is stopped, and the valve 11 returns to the neutral state, and as shown in FIG. 8C,
The solenoid energizing device 25 energizes the lowering solenoid 17 for a time t' to switch the switching valve 11 to the lowering state for a short time.

Therefore, the cycle T for energizing the rising solenoid 16 set in the mechanism 18 for replenishing pressure oil to the accumulator 12 is shorter than the energizing time t, and the height above the ground of the reaping pretreatment section A is set to the set height. If the temperature rises above this level, the short-time switching valve 11
is switched to the lowering state, the oil pressure is lowered to pressure _P3 , and the reaping pretreatment section A is lowered to a height close to that suitable for floating work.

Incidentally, when the floating operation using the accumulator 12 is not performed, the on-off valve 28 is kept closed.

[Another example]

In carrying out the present invention, a mechanism 18 for replenishing pressure oil to the accumulator 12, and
Based on the detection result that the height above the ground of the reaping pre-processing section A has exceeded the set height, the switching valve 1
The specific structure of the mechanism 27 for switching the position 1 to the lowered state for a short period of time can be modified in various ways.

Moreover, the set height in the present invention is a concept that includes not only a fixed height but also a set height within a fixed range with an upper limit and a lower limit.

[Brief explanation of the drawing]

The drawings show an embodiment of the elevating device for the reaping pre-processing section of the reaping harvester according to the present invention. Fig. 1 is a system diagram of the elevating device, and Fig. 2 shows the mechanism for replenishing pressure oil and the mechanism for switching to the lowering state. An explanatory diagram showing the operating state, FIG. 3 is an overall side view of the reaping harvester. A... Reaping pre-processing section, 10... Hydraulic cylinder for lifting, 11... Switching valve, 12... Accumulator, 18... Mechanism for replenishing pressure oil, 24... Ground height detection device, 26... Hydraulic pressure Circuit, 27... Mechanism for switching to the descending state.

Claims (1)

[Scope of utility model registration request] This machine is provided with a lifting hydraulic cylinder 10 that drives and lowers the reaping pre-processing section A, and a switch that switches oil passages to supply or discharge hydraulic oil for lifting operations to the lifting hydraulic cylinder 10. In a reaping pre-processing part elevating device for a reaping harvester in which a valve 11 is interposed in a hydraulic circuit 26, an accumulator 1 is provided in an oil path between the elevating hydraulic cylinder 10 and the switching valve 11 in the hydraulic circuit 26.
2 are connected and disposed in a communicating state, and a height above the ground detecting device 24 is provided in the pre-reaping treatment section A, and the height above the ground of the pre-reaping processing section A detected by the height above the ground detecting device 24 is lower than or equal to a set height. A pressure oil replenishment mechanism 18 that replenishes pressure oil to the accumulator 12 by intermittently switching the switching valve 11 to the upward state based on the detection result of the summer weather, and a pressure oil replenishment mechanism 18 that replenishes pressure oil to the accumulator 12 based on the detection result of the temperature, and a height above the ground of the reaping pretreatment section A are adjusted. A mechanism 27 for switching the switching valve 11 to a lowered state for a set time based on a detection result that the height has exceeded a set height.