Walking type work machine

Abstract

To provide a walking type work machine capable of suppressing energy consumption and reducing noise without requiring a troublesome operation.SOLUTION: A walking type work machine includes: a driving source 11 capable of changing output rotation; a main clutch 31 capable of permitting / shutting off power transmission from the driving source 11 to a transmission downstream side; speed setting means 19 capable of setting target speed of the driving source 11 through a manual operation; clutch detection means S1 for detecting whether the main clutch 31 is in an engaged state or disengaged state; and a control device CU for controlling an operation of the driving source. The control device CU controls the operation of the driving source 11 so as to reach the target speed when the engaged state is detected on the basis of the detection result obtained by the clutch detection means S1, and controls the operation of the driving source 11 so as to reach set speed lower than the target speed when the disengaged state is detected.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] A walking type working machine is equipped with an engine as a drive source, and is provided with a main clutch capable of disconnecting the power transmission from the engine to the transmission downstream side. Near the steering handle, there are provided a main clutch lever for operating the main clutch to engage and disengage, a throttle lever for adjusting the engine rotation, and the like. And, regardless of the operation of engaging and disengaging the main clutch, the output rotation of the engine is adjusted to the target speed set by the throttle lever (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above conventional configuration, as the set value of the throttle lever, when performing work running, since the driving load is large, the output rotation of the engine is generally set to a high output rotation close to the maximum output. When the work is interrupted, the main clutch is disengaged, but even in such a disengaged state of the main clutch, the output rotation of the engine is maintained at the above-described high output rotation. If this interrupted state continues for a long time, there are disadvantages that the fuel (energy) of the engine is wasted and a large driving noise becomes a noise.

[0005] Therefore, when the interruption becomes long, the operator will operate the throttle lever to reduce the output rotation of the engine. However, when resuming work after an interruption, an operation to return the throttle lever to its original state is required. In particular, when such interruptions are repeated, the operations of reducing the throttle lever and returning it to its original state must be repeated, which is troublesome.

[0006] Therefore, there has been a demand for a walking-type work machine that can suppress energy consumption and reduce noise without troublesome operations.

Means for Solving the Problem

[0007] The characteristic configuration of the walking-type work machine according to the present invention includes a drive source whose output rotation can be changed, a main clutch capable of interrupting the power transmission from the drive source to the transmission downstream side, speed setting means capable of setting the target speed of the drive source by manual operation, clutch detection means for detecting whether the main clutch is in the engaged state or the disengaged state, and a control device for controlling the operation of the drive source. The control device controls the operation of the drive source to reach the target speed when the engaged state is detected based on the detection result of the clutch detection means, and controls the operation of the drive source to reach a set speed lower than the target speed when the disengaged state is detected.

[0008] According to the present invention, based on the detection result of the clutch detection means, the operation of the drive source is controlled so that it is driven at the target speed if the main clutch is in the engaged state, and is driven at a low set speed if the main clutch is in the disengaged state.

[0009] As a result, by simply operating the main clutch to engage or disengage, work can be efficiently performed at high speed during the working state, and when the work is interrupted, the driving noise can be reduced, energy consumption can be decreased, and the driving noise can be minimized.

[0010] Accordingly, it has become possible to provide a walking-type working machine that can suppress energy consumption and reduce noise without cumbersome operation.

[0011] In the present invention, it is preferable that an artificial operation tool capable of operating the main clutch to engage and disengage is provided, and the clutch detection means is a detection switch that detects that the operation tool has been operated to the clutch-engaged position or the clutch-disengaged position.

[0012] According to this configuration, the main clutch is engaged and disengaged by manually operating the operation tool, and the operation position of the operation tool is detected by the detection switch, so that the determination of engagement and disengagement can be reliably performed.

[0013] In the present invention, it is preferable that the drive source is an engine provided with an electronically controlled fuel supply device.

[0014] According to this configuration, it is possible to accurately adjust the fuel supply amount and intake air amount to the engine by electronic control, and the output rotation of the drive source (engine) can be adjusted well.

[0015] In the present invention, starting command means for commanding the start of the engine is provided, and when the start of the engine is commanded by the starting command means, the control device permits the start of the engine when the disengaged state is detected by the clutch detection means, and is configured to restrain the engine when the disengaged state is detected by the clutch detection means, which is preferable.

[0016] According to this configuration, engine start restraint can be performed using the detection result of the clutch detection means. Therefore, it is not necessary to separately provide a dedicated command switch for start restraint, and the sharing of members can be achieved.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0018] Hereinafter, an embodiment of a walking type management machine, which is an example of a walking type work machine according to the present invention, will be described with reference to the drawings. The present invention is not limited to the following embodiments, and various modifications are possible without departing from the gist thereof.

[0019] In addition, the front-rear direction and the left-right direction in the description of this embodiment are described as follows unless otherwise specified. That is, the forward traveling direction on the front side during the working 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".

[0020] 〔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 temperature, stabilizing the operation of the engine 11, and realizing detailed control.

[0021] On the rear side of the engine frame 10, a transmission case 2 that constitutes the airframe frame 1 together with the engine frame 10 is integrally connected. The engine 11 and the transmission case 2 are interlocked and connected via a belt transmission mechanism 12 so that power can be transmitted.

[0022] 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.

[0023] On the lower part of the front case 2A, the left and right traveling devices 13 are supported via an 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.

[0024] On the rear case 2B, a working device 14 is supported via a 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.

[0025] The power of the engine 11 is transmitted to a gear shifting mechanism (not shown) inside the transmission case 2 via the belt transmission mechanism 12. The belt transmission mechanism 12 is configured to be able to engage and disengage power transmission by a clutch operation arm 12a. The belt transmission mechanism 12 and the clutch operation arm 12a constitute a main clutch 31 (Figure 3) that interrupts power transmission to the traveling drive system and the working drive system.

[0026] Inside the transmission case 2, a working clutch 32, a traveling clutch 33, and a differential mechanism 34 are provided (see Figure 3). The power from the main clutch 31 is branched and transmitted to the working clutch 32 and the traveling clutch 33.

[0027] The working clutch 32 engages and disengages the power transmission to the working device 14. The traveling clutch 33 engages and disengages 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. The working clutch 32 and the differential mechanism 34 are examples of an operating device Y described later, i.e., a slewing operating device.

[0028] 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, it is possible to perform a shift operation and a forward / backward switching operation of the traveling device 13, and a forward / reverse rotation operation of the working device 14.

[0029] The steering handle 16 extends rearward from the rear part of the transmission case 2 toward the rear of the machine body. A slewing lever 17, a stop switch 18, and a throttle lever 19 as a speed setting means are arranged on the right side portion of the steering handle 16. A main clutch lever 3 as an artificial operation type operating tool capable of engaging and disengaging the main clutch is arranged on the rear end side of the steering handle 16.

[0030] When the slewing lever 17 is in the engaged position, the working 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 regulate the differential of the traveling device 13 (differential lock disengaged). When the slewing lever 17 is in the disengaged position, the working clutch 32 is in a state where power transmission occurs (clutch engaged), and the differential mechanism 34 is in a state where it regulates the differential of the traveling device 13 (differential lock engaged).

[0031] The stop switch 18 is wired to the control system of the engine 11 for use in stopping the engine 11.

[0032] 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.

[0033] In the walking-type management machine configured as described above, the operator operates the walking-type management machine while holding the steering wheel 16 and walks together with the walking-type management machine that is traveling. Turning is performed by the operator turning the steering wheel 16 left and right to change the traveling direction of the walking-type management machine.

[0034] 〔Power transmission system and operation system〕 The walking-type management machine of this embodiment includes an engine 11 as a drive source whose output rotation can be changed, a main clutch 31 that can cut off the power transmission from the engine 11 to the transmission downstream side, a throttle lever 19 as a speed setting means that can set the target speed of the engine 11 by manual operation, a clutch detection sensor S1 as a clutch detection means for detecting whether the main clutch 31 is engaged or disengaged, and a control device CU that controls the operation of the engine 11. Based on the detection result of the clutch detection sensor S1, when the engaged state is detected, the control device CU controls the operation of the engine 11 to reach the target speed, and when the disengaged state is detected, it controls the operation of the engine 11 to reach a set speed lower than the target speed.

[0035] Also, when the turning lever 17 as the operating tool X is switched from the engaged position to the disengaged position, the control device CU gradually increases the output rotation of the engine 11 toward the set speed.

[0036] Furthermore, a shift detection sensor S2 as a forward / backward detection means for detecting whether the transmission 2C is in the forward state or the reverse state is provided, and a signal from the sensor S2 is transmitted to the control device CU via the transmission line 15b. Based on the detection result of the shift detection sensor S2, when the forward state is detected, the control device CU controls the operation of the engine 11 to reach the target speed, and when a transition from the forward state to the reverse state is detected, it controls the operation of the engine 11 to reach a set speed lower than the target speed. Then, when switching from the reverse state to the forward state, the output rotation of the engine 11 is gradually increased from the neutral speed toward the target speed set by the throttle lever 19.

[0037] In this embodiment, the device to be operated Y is provided with a turning operation device (working clutch 32 and differential mechanism 34) that can be switched between a turning operation state and a straight-ahead operation state. When the operating tool X (turning lever 17) is switched from the first operation state to the second operation state, the turning operation device (working clutch 32 and differential mechanism 34) is switched from the turning operation state to the straight-ahead operation state. Also, as the device to be operated Y, a transmission 2C that can be switched between a forward state and a reverse state is provided. When the operating tool X (main transmission lever 15) is switched from the first operation state (reverse position) to the second operation state (forward position), it is switched from the reverse state to the forward state.

[0038] Specifically, it will be described. Fig. 3 shows the power transmission system and the operation system of the walking type management machine of this embodiment.

[0039] The power transmission system will be described. The power from the engine 11 is transmitted to the work device 14 via the main clutch 31, the transmission 2C, and the working clutch 32. The power from the engine 11 is transmitted to the traveling device 13 via the main clutch 31, the transmission 2C, the traveling clutch 33, and the differential mechanism 34. The transmission 2C can transmit the power from the engine 11 to the traveling device 13 and can also switch between forward and reverse of the traveling device 13. Note that the traveling clutch 33 is not necessarily required, and a configuration without the traveling clutch 33 may be adopted.

[0040] The operation system will be described. When the walking type management machine turns, the turning lever 17 is operated by the operator from the cut-off position to the engaged position, and when it changes from the turning state to the straight-ahead state, it is operated by the operator from the engaged position to the cut-off position.

[0041] 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 off position to the on 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 on position to the off position, the working clutch 32 changes from a state of not transmitting power to a state of transmitting power.

[0042] 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 off position to the on 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 on position to the off 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. Note that the connection between the slewing lever 17 and the working clutch 32 or the differential mechanism 34 is not limited to a configuration mechanically connected using an operating wire, and a configuration in which the working clutch 32 or the differential mechanism 34 is switched by an actuator that operates by operating the slewing lever 17 may be used.

[0043] The operation received by the slewing lever 17 is configured to be electrically transmitted to the control device CU. That is, it is detected that the slewing lever 17 has been operated to the on position by a switch (for example, a limit switch) (not shown) that contacts the slewing lever 17, and a signal from the switch is transmitted to the control device CU via the transmission line 17c.

[0044] The operation received by the throttle lever 19 is configured to be transmitted to the control device CU. That is, a sensor (not shown) that detects the position of the throttle lever 19 is provided, and a signal from the sensor is transmitted to the control device CU via the transmission line 19a.

[0045] 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.

[0046] It is configured to electrically transmit the operation received by the main clutch lever 3 to the control device CU. That is, a clutch detection sensor S1 that comes into contact with the lever 3 and detects this when the main clutch lever 3 is operated to the engaged position is provided in the vicinity of the main clutch lever 3. The clutch detection sensor S1 is composed of, for example, a limit switch or the like. It is configured to transmit a signal from the clutch detection sensor S1 to the control device CU via a transmission line 3b.

[0047] 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.

[0048] The control device CU controls the electronic control fuel supply device FE based on the operation received by the throttle lever 19 to control the rotational speed of the engine 11.

[0049] In this embodiment, when the control device CU detects the engaged state of the main clutch 31 based on the detection result of the clutch detection sensor S1, it controls the operation of the engine 11 so that the engine speed becomes the target speed set by the throttle lever 19. When the disengaged state of the main clutch 31 is detected, it controls the operation of the engine 11 so that the engine speed becomes a set speed lower than the target speed.

[0050] Specifically, this control is premised on the engine 11 having started and being in a rotational operation state. When the engine 11 has started and the main clutch lever 3 has been engaged, that is, when the clutch detection sensor S1 detects the engaged state of the main clutch 31, the electronic control fuel supply device FE is controlled so that the output rotation speed of the engine 11 becomes the target speed set by the throttle lever 19, thereby controlling the rotational speed of the engine 11.

[0051] The target speed is set by the operator's operation of the throttle lever 19. When performing tilling work with the work implement 14 while traveling, since the traveling load and the driving load of the work implement 14 are large, a value is set as the target speed such that it becomes a large output rotation speed close to the maximum output of the engine 11 in consideration of work efficiency.

[0052] Then, when the work is interrupted and the main clutch lever 3 is disengaged, that is, when the clutch detection sensor S1 detects the disengaged state of the main clutch 31, the electronic control fuel supply device FE is controlled so that the output rotation speed of the engine 11 becomes the set speed set to a value lower than the target speed, thereby controlling the rotational speed of the engine 11. However, when, for example, an idling speed or a target speed close thereto is set by the operation of the throttle lever 19, the control to reduce the rotational speed of the engine 11 is not executed.

[0053] The control content of the control device CU will be described with reference to the time chart of FIG. 4. When the main clutch 31 is engaged and the first set value M1 is set by the throttle lever 19, the control device CU controls the electronic control fuel supply device FE so that the output rotational speed of the engine 11 becomes the first target speed N1 as the target speed corresponding to the first set value M1. At this time, if the engine 11 is in an unloaded state, the output rotational speed of the engine 11 becomes the first target speed N1. However, when performing tillage work, since the driving load is large, the actual rotational speed of the engine 11 may drop below the first target speed N1.

[0054] At the start of work, the transmission 2C switches from the neutral state to the forward state. At this time, even if the shift detection sensor S2 detects that the state has switched to the forward state, the output rotational speed of the engine 11 maintains the first target speed N1.

[0055] During the operation by forward travel, when the shift detection sensor S2 detects a transition from the forward state to the reverse state, the electronic control fuel supply device FE is controlled so that the output rotational speed of the engine 11 becomes the third target speed N3 lower than the first target speed N1. In this way, when switching to the reverse state, the output rotation of the engine 11 can be reduced without operating the throttle lever 19, and reverse travel can be started at a low speed without the hassle of operation. The third target speed N3 may be a value close to the idling rotational speed which is the lower limit value of the characteristics of the engine 11, but if it is a value higher than the idling rotational speed, it is easier to resume work.

[0056] When turning is performed by operating the turning lever 17 to the engaged position during the operation, the output rotation of the engine 11 rapidly drops to the third target speed N3. In this embodiment, the turning speed is set to be the same as the third target speed N3, but it may be a different value. It may be a value close to the idling rotational speed which is the lower limit value of the characteristics of the engine 11, but if it is a value slightly higher than the idling rotational speed, it is easier to resume work.

[0057] When the turning lever 17 is switched from the engaged position to the disengaged position, the output rotation of the engine 11 gradually increases. That is, it slowly increases from the third target speed N3 (turning speed) toward the first target speed N1. However, when the turning lever 17 is switched from the engaged position to the disengaged position and a value close to or lower than the third target speed N3 is set by the throttle lever 19, the speed increase control (gradual increase) is not performed. For example, when a value lower than a predetermined threshold is set by the throttle lever 19, the control unit CU does not perform the speed increase control (gradual increase) when the turning lever 17 is switched from the engaged position to the disengaged position, and controls the output rotation of the engine 11 to be the value set by the throttle lever 19.

[0058] When the operation is interrupted and the main clutch 31 is switched to the disengaged state, the control unit CU controls the electronic control fuel supply device FE so that the output rotation speed of the engine 11 becomes the fourth target speed N4, which is a set speed lower than the first target speed N1. In this way, when the main clutch 31 is in the disengaged state, the output rotation of the engine 11 can be reduced without operating the throttle lever 19, eliminating the annoyance of operation, suppressing wasteful fuel consumption, and reducing noise. The fourth target speed N4 may be lower than the third target speed N3 or higher than the third target speed N3 as shown in FIG. 4.

[0059] The fourth target speed N4 is set to a value slightly higher than the lower limit value (idling speed) of the characteristics of the engine 11. If the engine speed is reduced to the idling speed, it will then take time to return to the original state, which is not good in terms of work efficiency.

[0060] When the interruption of the operation ends and the main clutch 31 is switched to the engaged state, the control unit CU controls the electronic control fuel supply device FE so that the output rotation speed of the engine 11 becomes the first target speed N1. Thereby, subsequent operations can be performed efficiently.

[0061] During operation, if the operator operates the throttle lever 19 and switches to a second set value M2 lower than the first set value M1, the control device CU controls the electronic control fuel supply device FE so that the output rotational speed of the engine 11 becomes a second target speed N2 corresponding to the second set value M2. For example, when traveling along a ridge without performing tilling work, since the operator has room for operation, the operator can operate the throttle lever 19, and can reduce the output of the engine 11 as much as possible to reduce noise.

[0062] 〔Another Embodiment〕 The present invention is not limited to the configurations exemplified in the above-described embodiments. Hereinafter, typical other embodiments of the present invention will be exemplified.

[0063] (1) It may be configured to include a key switch as starting command means for commanding starting of the engine 11 and a starter motor for starting the engine by operating the key switch. When starting of the engine is commanded by the key switch, the control device CU permits starting of the engine 11 when the clutch detection sensor S1 detects a disengaged state, and restrains starting of the engine 11 when the clutch detection sensor S1 detects a disengaged state. That is, the clutch detection sensor S1 may also be used for engine start restraint.

[0064] (2) The clutch detection sensor S1 is not limited to a limit switch, and may be a non-contact detection sensor, or may detect engagement of the main clutch 31 by mechanical movement using a mechanical interlocking mechanism.

[0065] (3) When the engine 11 is operating, if the main clutch 31 is disengaged and the state where the main clutch 31 is not operated continues for a set time or more, the operation of the engine 11 may be stopped. According to this configuration, fuel consumption can be further suppressed and noise can be reduced.

[0066] (4) The engine 11 may not be equipped with an electronically controlled fuel supply device FE. That is, the engine 11 may be one in which the fuel supply amount to the engine is adjusted by a mechanical carburetor or the like.

[0067] (5) The walking type management machine may be equipped with an electric motor as a drive source instead of the engine 11.

[0068] (6) Instead of the differential mechanism 34, a side clutch mechanism may be provided.

Industrial Applicability

[0069] The present invention is applicable to a walking type working machine. For example, it can be applied to a walking type management machine, a walking type rice transplanter, a walking type vegetable transplanter, etc.

Explanation of Signs

[0070] 3 Main clutch lever (operating tool) 11 Engine (drive source) 19 Throttle lever (speed setting means) 31 Main clutch CU Control device FE Electronically controlled fuel supply device S1 Clutch detection sensor (clutch detection means)

Claims

1. a drive source whose output rotation can be changed; a main clutch capable of interrupting the power transmission from the drive source to the transmission downstream side; speed setting means capable of setting a target speed of the drive source by manual operation; clutch detection means for detecting whether the main clutch is engaged or disengaged; a control device for controlling the operation of the drive source, and is provided with, the control device, based on the detection result of the clutch detection means, when the engaged state is detected, controls the operation of the drive source so as to reach the target speed, and when the disengaged state is detected, controls the operation of the drive source so as to reach a set speed lower than the target speed. A walking type working machine.

2. is provided with a manually operable operating tool for engaging and disengaging the main clutch, The walking type working machine according to claim 1, wherein the clutch detection means is a detection switch that detects that the operating tool has been operated to the clutch engaged position or the clutch disengaged position.

3. The walking type working machine according to claim 1 or 2, wherein the drive source is an engine provided with an electronically controlled fuel supply device.

4. is provided with starting command means for commanding the start of the engine, The control device is configured to allow the engine to start when the starting command means commands the start of the engine and the clutch detection means detects the disengaged state, and to inhibit the start of the engine when the clutch detection means detects the disengaged state. The walking type working machine according to claim 3.

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