Walking type work machine

Abstract

To provide a walking type work machine capable of securing stability of operations without troublesomeness when a driving load of a work device is reduced suddenly while performing work.SOLUTION: A walking type work machine is provided with a work device 14, a driving source 11 for driving the work device 14, work state detection means S1 for detecting whether or not the work device 14 is in a work state in which the work device is performing work, load detection means S2 for detecting the magnitude of the load of the work device 14, and a control device CU for controlling the driving state of the work device 14. The control device CU reduces the driving speed of the work device 14 or stops the driving when the load detected by the load detection means S2 is a preset amount or less in the state that the work state is detected by the work state detection means S1.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a walking type working machine such as a walking type management machine or a walking type rice transplanter, for example.

Background Art

[0002] In a walking type management machine as an example of a walking type working machine, an engine is mounted as a drive source, a clutch capable of switching on and off the power transmission from the engine to the transmission downstream side is provided, and near the operation handle, a clutch lever for operating the clutch on and off, a throttle lever for adjusting the engine rotation, etc. are provided. (For example, refer to Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When agricultural work is performed in a field by a walking type management machine, the operator operates while holding the operation handle and performs tilling work while walking with the traveling walking type working machine. When working, the working device may lift off the field surface, or the working device may ride on a hard object such as a stone and rotate idly. In such a case, since the driving load of the working device suddenly decreases, the driving speed may suddenly increase.

[0005] When working, the output of the engine is adjusted to a large value close to the maximum output. Therefore, as described above, when the driving load suddenly decreases, the speed of the working device suddenly increases and continues to rotate at a high speed, which may cause the operation by the operator to become unstable. Although the operator can reduce the speed of the working device by operating the throttle lever to reduce the output of the engine, the operation becomes complicated.

[0006] Therefore, there has been a demand for a walking work machine capable of ensuring the stability of operation without annoyance when the driving load of the work device suddenly decreases during work.

Means for Solving the Problem

[0007] The characteristic configuration of the walking work machine according to the present invention includes a work device, a drive source for driving the work device, a work state detection means for detecting whether the work device is in a work state where work is being performed, a load detection means for detecting the magnitude of the load of the work device, and a control device for controlling the driving state of the work device. The control device decelerates the driving speed of the work device or stops the driving when the load detected by the load detection means becomes equal to or less than a set value in a state where the work state is detected by the work state detection means.

[0008] According to the present invention, in a work state where the work device is performing work, when the load of the work device decreases to equal to or less than a set value, automatically, the driving speed of the work device is decelerated or the driving of the work device is stopped. As a result, for example, if the work device floats from the field surface or contacts a hard object and idles, it is possible to avoid the situation where the work device continues to rotate at high speed and the driving operation by the operator becomes unstable.

[0009] Therefore, it has become possible to provide a walking work machine capable of ensuring the stability of operation without annoyance when the driving load of the work device suddenly decreases during work.

[0010] In the present invention, it is preferable that a clutch for interrupting the power transmission from the drive source to the work device is provided, and the control device operates to disengage the clutch when the load becomes equal to or less than a set value.

[0011] According to this configuration, when the load on the working device decreases to or below a set value, the driving of the working device is automatically stopped, so it is possible to reliably avoid the operation of the operator becoming unstable.

[0012] In the present invention, the drive source is an engine provided with an electronically controlled fuel supply device, and it is preferable that the control device decelerates the driving speed of the engine or stops driving the engine when the load becomes equal to or less than a set value.

[0013] According to this configuration, since the engine is provided with an electronically controlled fuel supply device, it is possible to accurately adjust the fuel supply amount and intake air amount to the engine by electronic control, and it is possible to favorably adjust the output rotation of the drive source (engine).

[0014] In the present invention, a switching mechanism that can be switched between a turning operation state and a straight traveling operation state is provided, and it is preferable that the working state detection means detects the working state depending on whether the switching mechanism is in the straight traveling operation state.

[0015] According to this configuration, the switching mechanism can switch between a turning operation state suitable for turning and a straight traveling operation state suitable for straight traveling. When working in the field, it is carried out while going straight, so it is in the straight traveling operation state. Therefore, it is possible to detect that it is the working state by being in the straight traveling operation state.

[0016] In the present invention, a clutch that can cut off the power transmission from the drive source to the working device is provided, and it is preferable that the working state detection means detects the working state depending on whether the clutch is engaged.

[0017] According to this configuration, when working in the field, power is transmitted to the working device via the clutch, so it is possible to detect that it is the working state depending on the state of the clutch.

[0018] In the present invention, it is preferable that the working state detection means detects the working state based on whether the PTO shaft that transmits the power from the drive source to the working device is rotating or not.

[0019] According to this configuration, when working in the field, power is transmitted to the working device via the PTO shaft, so it is possible to detect that it is in the working state based on the rotation state of the PTO shaft.

[0020] In the present invention, it is preferable that the load detection means detects the load based on the driving torque of the PTO shaft that transmits the power from the drive source to the working device.

[0021] According to this configuration, when working in the field, power is transmitted to the working device via the PTO shaft, and the driving torque of the PTO shaft varies according to the magnitude of the driving load, so the load can be detected by the driving torque.

[0022] In the present invention, it is preferable that the load detection means detects the load based on the variation in the rotational speed of the PTO shaft that transmits the power from the drive source to the working device.

[0023] According to this configuration, when the driving load becomes smaller than the set value, the rotational speed of the PTO shaft increases compared to when a load is applied, so the load can be detected thereby.

Brief Description of the Drawings

[0024]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0025] Hereinafter, an embodiment of a walking-type management machine, which is an example of a walking-type working machine according to the present invention, will be described with reference to the drawings. Note that the present invention is not limited to the following embodiments, and various modifications are possible without departing from the gist thereof.

[0026] In addition, the front-rear direction and the left-right direction in the description of the present embodiment are described as follows unless otherwise specified. That is, the forward traveling direction on the forward side during the work travel of the walking-type management machine (see the arrow FR in FIGS. 1 and 2) is "front", the traveling direction to the reverse side (see the arrow BK in FIGS. 1 and 2) is "rear", and the direction corresponding to the right side based on the forward posture in the front-rear direction (see the arrow RH in FIG. 2) is "right", and similarly, the direction corresponding to the left side (see the arrow LH in FIG. 2) is "left".

[0027] 〔Overall Configuration〕 As shown in FIG. 1, an engine 11 serving as a drive source is mounted on an engine frame 10 that forms a part of the machine body frame 1 of the traveling machine body of the walking-type management machine. In the present embodiment, the engine 11 is provided with an electronically controlled fuel supply device FE (FIG. 3). The electronically controlled fuel supply device FE forcibly injects and supplies fuel into the combustion cylinder by an actuator and adjusts the intake air amount by a throttle valve, and can change and adjust the rotational speed of the engine 11. That is, the electronically controlled fuel supply device FE includes an electronically controlled fuel injection device. Further, the electronically controlled fuel supply device FE has a function of an electronic governor that suppresses fluctuations in the rotational speed of the engine 11. Therefore, there are advantages such as reducing the influence of the external environment such as the temperature, stabilizing the operation of the engine 11, and realizing detailed control.

[0028] A transmission case 2 that forms the machine body frame 1 together with the engine frame 10 is integrally connected to the rear side of the engine frame 10. The engine 11 and the transmission case 2 are interlocked and connected via a belt transmission mechanism 12 so that power can be transmitted.

[0029] The transmission case 2 is formed in a bifurcated shape including a front case 2A extending downward and a rear case 2B extending obliquely rearward and downward.

[0030] On the lower part of the front case 2A, the left and right traveling devices 13 are supported via the axle 20. In this embodiment, the traveling device 13 is a wheel. The traveling device 13 may be a device of other forms, such as a crawler traveling device.

[0031] On the rear case 2B, the working device 14 is supported via the drive shaft 21. In this embodiment, the working device 14 is a rotary tilling device. The working device 14 may be a device of other forms, such as a ridging machine or a seeding machine.

[0032] The power of the engine 11 is transmitted via the belt transmission mechanism 12 to a gear shifting mechanism (not shown) inside the transmission case 2. The belt transmission mechanism 12 is configured such that the power transmission can be turned on and off by the clutch operation arm 12a. The belt transmission mechanism 12 and the clutch operation arm 12a constitute a main clutch 31 (FIG. 3) that intermittently transmits power to the traveling drive system and the working drive system.

[0033] Inside the transmission case 2, a working clutch 32, a traveling clutch 33, and a differential mechanism 34 are provided (see FIG. 3). The power from the main clutch 31 is branched and transmitted to the working clutch 32 and the traveling clutch 33.

[0034] The working clutch 32 turns on and off the power transmission to the working device 14. The traveling clutch 33 turns on and off the power transmission to the traveling device 13 via the differential mechanism 34. The differential mechanism 34 can regulate the differential of the left and right traveling devices 13.

[0035] The main shift lever 15 extends obliquely rearward and upward from the upper part of the transmission case 2. By operating this main shift lever 15, the shift operation and the forward and reverse switching operation of the traveling device 13, and the forward and reverse rotation operation of the working device 14 can be performed.

[0036] The steering handle 16 extends rearward from the rear part of the mission case 2 toward the rear of the machine body. A turning lever 17, a stop switch 18, and a throttle lever 19 are arranged on the right side portion of the steering handle 16. A main clutch lever 3 capable of engaging and disengaging the main clutch is arranged on the rear end side of the steering handle 16.

[0037] When the turning lever 17 is in the engaged position, the work clutch 32 is in a state where power transmission does not occur (clutch disengaged), and the differential mechanism 34 is in a state where it does not restrict the differential of the traveling device 13 (differential lock disengaged). When the turning lever 17 is in the disengaged position, the work clutch 32 is in a state where power transmission occurs (clutch engaged), and the differential mechanism 34 is in a state where it restricts the differential of the traveling device 13 (differential lock engaged).

[0038] The stop switch 18 is wired to the control system of the engine 11 for use in stopping the engine 11.

[0039] The throttle lever 19 is connected to a control device CU that controls the electronic control fuel supply device FE for use in operating the rotational speed of the engine 11.

[0040] In the walking type management machine configured as described above, the operator holds the steering handle 16 to operate the walking type management machine and walks together with the walking type management machine while it is traveling. Turning is performed by the operator turning the steering handle 16 left and right to change the traveling direction of the walking type management machine.

[0041] 〔Power transmission system and operation system〕 The walking type management machine of the present embodiment includes a working device 14, a drive source (engine) 11 that drives the working device 14, a working state detection means for detecting whether or not the working device 14 is in a working state in which work is being performed, a load detection means for detecting the magnitude of the load of the working device 14, and a control device CU that controls the driving state of the working device 14. When the load detected by the load detection means becomes equal to or less than a set amount in a state where the working state is detected by the working state detection means, the control device CU stops driving the working device 14.

[0042] That is, a switching mechanism K capable of switching between a turning operation state and a straight traveling operation state is provided, and the working state detecting means detects the working state based on whether the switching mechanism K is in the straight traveling operation state. Further, the load detecting means detects the load based on the driving torque of the PTO shaft 14a that transmits the power from the engine 11 to the working device 14. And a clutch 32 for switching the power transmission from the engine 11 to the working device 14 on and off is provided, and the control device C performs a disengagement operation of the clutch 32 when the load becomes equal to or less than the set amount.

[0043] Specifically describe. Fig. 3 shows the power transmission system and the operation system of the walking type management machine of the present embodiment.

[0044] Describe the power transmission system. The power from the engine 11 is transmitted from the PTO shaft 14a to the working device 14 via the main clutch 31 and the working clutch 32 which is an example of a clutch. The power from the engine 11 is transmitted to the traveling device 13 via the main clutch 31, the traveling clutch 33, and the differential mechanism 34.

[0045] The working clutch 32 can be switched on and off by manual operation as described later, but in addition to manual operation, it is configured to be able to perform a disengagement operation using an actuator 36 such as an electric motor.

[0046] Describe the operation system. The turning lever 17 is operated by the operator from the disengaged position to the engaged position when the walking type management machine turns, and is operated by the operator from the engaged position to the disengaged position when changing from the turning state to the straight traveling state.

[0047] The slewing lever 17 and the working clutch 32 are mechanically connected by a first operating wire 17a. The first operating wire 17a mechanically transmits the operation received by the slewing lever 17 to the working clutch 32. When the slewing lever 17 is operated from the disengaged position to the engaged position, the working clutch 32 changes from a state of transmitting power to a state of not transmitting power. Then, the operation of the working device 14 stops. When the slewing lever 17 is operated from the engaged position to the disengaged position, the working clutch 32 changes from a state of not transmitting power to a state of transmitting power.

[0048] The slewing lever 17 and the differential mechanism 34 are mechanically connected by a second operating wire 17b. The second operating wire 17b mechanically transmits the operation received by the slewing lever 17 to the differential mechanism 34. When the slewing lever 17 is operated from the disengaged position to the engaged position, the differential mechanism 34 changes from a state of restricting the differential of the left and right traveling devices 13 to a state of not restricting the differential. Then, the operation of the left and right traveling devices 13 is permitted, and it becomes easier for the operator to turn the walking-type management machine. When the slewing lever 17 is operated from the engaged position to the disengaged position, the differential mechanism 34 changes from a state of not restricting the differential of the left and right traveling devices 13 to a state of restricting the differential.

[0049] The slewing lever 17, the first operating wire 17a, the working clutch 32, the second operating wire 17b, and the differential mechanism 34 constitute a switching mechanism K that can be switched between a slewing operation state and a straight-ahead operation state. And, in the vicinity of the slewing lever 17, a straight-ahead detection sensor S1 as a working state detection means that contacts the lever 17 and detects this when operated to the straight-ahead position is provided. The straight-ahead detection sensor S1 is composed of, for example, a limit switch or the like. The signal from the straight-ahead detection sensor S1 is configured to be transmitted to the control device CU via the second transmission line 17c.

[0050] It is configured to transmit the operation received by the throttle lever 19 to the control device CU. That is, it is provided with a sensor (not shown) that detects the position of the throttle lever 19, and the signal of that sensor is transmitted to the control device CU via the first transmission line 19a.

[0051] The main clutch lever 3 and the main clutch 31 are mechanically connected by a third operating wire 3a. The third operating wire 3a mechanically transmits the operation received by the main clutch lever 3 to the main clutch 31. When the main clutch lever 3 is operated to the disengaged position, the main clutch 31 is in the clutch disengaged state where power transmission is interrupted. When the main clutch lever 3 is operated to the engaged position, the main clutch 31 is in the clutch engaged state where the power of the engine 11 is transmitted to the transmission side. Then, the power of the engine 11 is transmitted to the traveling device 13 via the traveling clutch 33 and the differential mechanism 34, and is also transmitted to the working device 14 via the working clutch 32, and the tilling operation can be performed while traveling.

[0052] In the vicinity of the PTO shaft 14a, a torque detector S2 is provided as load detecting means for detecting the driving torque of the PTO shaft 14a when the PTO shaft 14a is rotationally driven. When the working device 14 enters the field and the tilling operation is being performed, the driving torque of the PTO shaft 14a increases. However, during the operation, when the working device 14 floats from the field surface or rides on a hard area of the field and so-called dashing occurs (hereinafter referred to as the idling state), since the working device 14 rotates freely, the driving torque of the PTO shaft 14a rapidly decreases.

[0053] The control device CU is a so-called ECU and includes a storage device ME and a CPU (not shown). The storage device ME includes an HDD, a non-volatile RAM, etc., and stores a program for controlling the walking type management machine, constant data, and temporary data. When the program is executed by the CPU, the functions of the control device CU described below are realized.

[0054] Based on the operation received by the throttle lever 19, the control device CU controls the electronic control fuel supply device FE so that the output rotation of the engine 11 becomes the target speed set by the throttle lever 19, and controls the rotational speed of the engine 11.

[0055] When performing tillage work with the working device 14 while the vehicle is moving, since the running load and the driving load of the working device 14 are large, in consideration of work efficiency, a value is set as the target speed such that it becomes a large output rotation close to the maximum output of the engine 11. And when it becomes an idling state as described above in the working state, the driving torque of the PTO shaft 14a rapidly decreases.

[0056] Therefore, when the control device CU detects that the straight-ahead state, that is, the working state, is detected by the straight-ahead detection sensor S1 and the torque (corresponding to the load) detected by the torque detector S2 becomes equal to or less than the set amount, the actuator 36 is operated to disengage the work clutch 32. As the set amount of the torque for determination, a value slightly larger than the value corresponding to the torque when the working device 14 is driven in a no-load state is set.

[0057] When the torque becomes equal to or less than the set amount, that is, when the idling state of the working device 14 is detected, by operating the clutch mechanism 35 to disengage, it is possible to avoid the disadvantage of causing the operator's operation to become unstable by driving the working device 14 to rotate uselessly, and it is possible to suppress wasteful fuel consumption.

[0058] After the work clutch 32 is disengaged, for example, after operating the throttle lever 19 to the minimum position and then operating it to a high position again, or after switching the turning lever 17 to the turning state and then switching it back to the straight-ahead state again, an artificial reset operation is performed. The work clutch 32 may be restored to the engaged state, or it may be automatically restored to the clutch-engaged state after a predetermined time has elapsed.

[0059] 〔Alternative Embodiment〕 The present invention is not limited to the configurations exemplified in the above-described embodiments. Hereinafter, representative alternative embodiments of the present invention will be exemplified.

[0060] (1) Instead of operating the work clutch 32, the control device CU may be configured to decelerate the driving speed of the engine 11 to the idling speed or a low speed close thereto when the load becomes equal to or less than the set amount. Alternatively, instead of decelerating the driving speed of the engine 11, the operation of the engine 11 may be stopped. Also, as a clutch that is disengaged when the load becomes equal to or less than the set amount, instead of the configuration of operating the work clutch 32 as in the above embodiment, for example, a dedicated clutch mechanism may be provided in the transmission system that transmits power from the work clutch 32 to the PTO shaft 14a, and the clutch mechanism may be disengaged using an actuator.

[0061] (2) As shown in FIG. 4, instead of the differential mechanism 34, a side clutch 41 that can be independently engaged and disengaged with respect to each of the left and right traveling devices 13 by operating the left and right side clutch levers 42, and instead of the turning lever, a work clutch lever 43 that commands the engagement and disengagement of the work clutch 32 may be provided. In this embodiment, the switching mechanism K is constituted by the side clutch 41, the side clutch lever 42, and an operation wire (42a) that connects the left and right side clutch levers 42 and the side clutch 41.

[0062] In this embodiment, as the work state detection means, the work state is detected based on whether the work clutch 32 is in the engaged state. Specifically, a work detection sensor S3 as the work state detection means that contacts the lever and detects this when the work clutch lever 43 is operated to the clutch engaged position is provided in the vicinity of the work clutch lever 43. The work detection sensor S3 is composed of, for example, a limit switch or the like. The signal from the work detection sensor S3 is configured to be transmitted to the control device CU via the third transmission line 4b.

[0063] (3) The operating state detection means may be configured to detect the operating state based on whether the PTO shaft that transmits the power from the engine to the working device is rotating. That is, as shown in FIG. 4, as the operating state detection means, a rotation sensor S4 for detecting the rotation speed of the PTO shaft 14a is provided. During operation, when the control device CU detects that the detected value of the rotation sensor S4 is equal to or higher than the set speed for operation determination, it determines that it is in the operating state.

[0064] (4) As the load detection means, it may be configured to detect the load based on the fluctuation of the rotation speed of the PTO shaft 14a that transmits the power from the engine 11 to the working device 14. That is, as the load detection means, a rotation sensor S4 for detecting the rotation speed of the PTO shaft 14a is provided. During operation, when the control device CU detects that the detected value of the rotation sensor S4 has risen suddenly from the speed corresponding to the operation to a rotation speed equal to or higher than the no-load determination set speed corresponding to no-load, it decelerates the driving speed of the working device 14 or stops the driving. During tilling work, the rotation speed of the PTO shaft 14a is lower than the no-load rotation speed due to the working load. However, when it is in the idling state, since the load disappears, it rises suddenly to the no-load rotation speed. Therefore, the idling state can be detected by such an increase in the rotation speed.

[0065] (5) As the load detection means, a pressure sensor for detecting the pressure sensed by the tilling claws 14t of the working device 14 during tilling work may be provided on the tilling claws 14t, and the load may be detected based on the fluctuation of the detected pressure. The control device CU can determine the idling state by detecting that the detected value of the pressure sensor has dropped suddenly from a high value corresponding to the operation to a low value corresponding to no-load.

[0066] (6) The engine 11 may not be provided with an electronically controlled fuel supply device FE. That is, the engine 11 may be one in which the rotation speed (operating amount) is adjusted by a mechanical carburetor or the like.

[0067] (7) The walking type management machine may be provided with an electric motor as a drive source instead of the engine 11.

Industrial Applicability

[0068] The present invention is applicable to a walking type working machine. For example, it is applicable to a walking type management machine, a walking type rice transplanter, a walking type vegetable transplanter, etc.

Explanation of Signs

[0069] 11 Engine (driving source) 14 Working device 14a PTO shaft 32 Working claim (clutch) 35 Clutch mechanism (clutch) CU Control device K Switching mechanism S1, S3 Working state detection means S2, S4 Load detection means

Claims

1. An operating device, a drive source for driving the operating device, operating state detection means for detecting whether or not the operating device is in an operating state in which work is being performed, load detection means for detecting the magnitude of the load on the operating device, a control device for controlling the driving state of the operating device, wherein the control device decelerates the driving speed of the operating device or stops the driving when the load detected by the load detection means is equal to or less than a set value in a state where the operating state is detected by the operating state detection means. A walking type working machine.

2. A clutch for interrupting the power transmission from the drive source to the operating device is provided, the control device operates to disengage the clutch when the load is equal to or less than a set value. The walking type working machine according to claim 1.

3. The drive source is an engine provided with an electronically controlled fuel supply device, the control device decelerates the driving speed of the engine or stops the driving of the engine when the load is equal to or less than a set value. The walking type working machine according to claim 1.

4. A switching mechanism capable of switching between a turning operation state and a straight traveling operation state is provided, the operating state detection means detects the operating state based on whether or not the switching mechanism is in the straight traveling operation state. The walking type working machine according to any one of claims 1 to 3.

5. A clutch capable of interrupting the power transmission from the drive source to the operating device is provided, the operating state detection means detects the operating state based on whether or not the clutch is engaged. The walking type working machine according to any one of claims 1 to 3.

6. the operating state detection means detects the operating state based on whether or not a PTO shaft for transmitting power from the drive source to the operating device is rotating. The walking type working machine according to any one of claims 1 to 3.

7. the load detection means detects the load based on the drive torque of a PTO shaft for transmitting power from the drive source to the operating device. The walking type working machine according to any one of claims 1 to 3.

8. the load detection means detects the load based on the variation in the rotational speed of a PTO shaft for transmitting power from the drive source to the operating device. The walking type working machine according to any one of claims 1 to 3.

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