JP2859123B2 - Lawn mower lifting mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a lawn mowing device which can be moved up and down and stopped via an actuator.
A first movable member that is displaced by an operation tool and a second movable member that is interlocked to the actuator via a release wire are opposed to each other so as to be relatively displaceable, and constitute a lifting drive switch that raises the actuator. Movable contacts and sliding contacts for the first and second movable members are separately provided, and the movable contacts and the sliding contacts for constituting a lowering drive switch for lowering the actuator are provided by the first and second movable members. Each of the second movable members is separately provided, and the ascending drive switch is turned on in accordance with the displacement operation of the first movable member by the ascending operation of the operating tool, so that the actuator is ascended, and the ascending of the actuator is performed. With the displacement operation of the second movable member interlocked with the operation, the raising drive switch is turned off and the actuator is stopped. Constitute the lift-up operation switches to the state, and, together with the actuator the downward drive switch is turned on with the displacement movement of the first movable member by lowering operation of the operating member is lowered operated,
Lawn mower of a lawn mower comprising the lowering drive switch in a state in which the lowering drive switch is turned off in accordance with the displacement operation of the second movable member in conjunction with the lowering operation of the actuator and the actuator is stopped. The present invention relates to a device lifting mechanism.

[0002]

2. Description of the Related Art Conventionally, as a lawn mowing device elevating mechanism for a lawn mower of this kind, for example, Japanese Patent Application No. Hei 5
No. -5495 has been proposed. In this conventional structure, the height position of the lawn mower relative to the body can be arbitrarily set by operating the operating tool, and the height of the lawn mowing apparatus can be changed only by operating the operating tool. there were.

[0003]

By the way, in the lawn mower having the above-mentioned conventional structure, the lawn mowing device is mowered while maintaining the height of the body thereof set by the operating tool as described above. The mowing height is also kept constant, but when there is a convex part such as a pile on the ground, the lawn mowing apparatus is temporarily raised while the lawn mower is being driven to avoid the convex part. After operating the operating tool and avoiding the protrusions, operate the operating tool while visually observing the lawn mower or the position of the operating tool so that the lawn mower is at the original height position. Thus, the height of the lawn mower with respect to the aircraft must be accurately corrected by manual operation. For this reason, every time there is a convex portion on the ground, the lawn mowing device must be raised to avoid the convex portion, and furthermore, the lawn mowing device must be artificially and accurately lowered to the predetermined mowing height position. However, the operation of descending with high accuracy has been troublesome. The present invention has been made in view of the above circumstances, and after temporarily raising a lawn mowing device during a mowing operation, it is simply and accurately performed to lower the lawn mowing device to an original mowing height position. It is an object of the present invention to provide a lawn mower lifting mechanism for a lawn mower that can be lowered.

[0004]

According to a first aspect of the present invention, there is provided a lawn mower lifting and lowering mechanism for a lawn mower according to the present invention, wherein the first movable member is fixed at a predetermined position with respect to the first movable member. And a lock mechanism for fixing the third movable member at an arbitrary position is provided. The operation and effect of this characteristic configuration are as follows.

[0005]

In other words, with the height position of the lawn mower set at a fixed position, the third movable member is displaced in advance so that the first movable member and the third movable member are positioned by the detent mechanism. If the third movable member is fixed by the lock mechanism in the positioned state, when the operating tool is operated to raise the lawn mower temporarily to operate the lifting device temporarily,
The first movable member is displaced so that the locking of the detent mechanism between the first movable member linked to the operating tool and the third movable member is released, but when the lawn mower is lowered to the original cutting height position, By operating the operating tool so that the first movable member and the third movable member are locked by the detent mechanism, the first movable member and the third movable member are lowered to the original cutting height position. still,
Whether or not the locking by the detent mechanism has been performed is determined by whether or not the operation of the operating tool becomes heavy at a specific location.

[0006]

Therefore, the cutting height is set to a preset cutting height by a simple operation of merely operating the operating tool so that the first movable member and the third movable member are locked by the detent mechanism. Since the lawn mowing device descends accurately, the operator does not need to check the height position of the lawn mowing device one by one or check the operating position of the operating tool one by one and operate with high accuracy. Sex has become very good.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a riding lawn mower as an example of a lawn mower. This riding lawn mower is disposed in a lower abdominal space between a front wheel 3 and a rear wheel 4 on a vehicle body having a boarding operation unit 1, a driving unit 2, a steering front wheel 3, a driving rear wheel 4, and the like. In this state, the lawn mower 5 is provided so as to be able to move up and down, and the vertical PTO shaft 6
Is transmitted to the lawn mowing device 5 via the belt-type transmission 7.

As shown in FIG. 2, a lift arm 9 supporting and suspending the lawn mower 5 via a link mechanism 8 is configured to be driven and oscillated by a double-acting hydraulic cylinder 10, and a three-position switching type electromagnetic motor is provided. When the raising solenoid 11 of the operation valve V is energized, the hydraulic cylinder 10 is shortened and the lawn mower 5 moves up. It is configured to be.

The raising and lowering operation section of the lawn mowing apparatus 5 is configured as shown in FIG. That is, in the operation case 13 disposed at an appropriate place of the boarding operation unit 1, a terminal block 14a having a fan shape in plan view is provided.
And a disk-shaped printed circuit board 15 as a second movable member are relatively rotatably mounted on a common axis P, and the terminal block 14a is provided outside the case 13 for setting the height of the lawn mower. By the rotation operation lever 16 as a tool,
The printed circuit board 15 is rotated by pulleys 17 provided in the operation case 13.

As shown in FIGS. 6 and 7, a sliding contact 18 connected to a power source Bu is formed on the printed circuit board 15 by printing, and the terminal block 14a is connected to an ascending drive circuit Du. A movable contact 19 and a movable contact 20 connected to the descent drive circuit Dd are provided. The operation case 13 is provided with a fixed contact 21 for upper limit control. The sliding contact 18 and these movable contacts 19 and 20 and the fixed contact 21, the ascending drive switch S shown in FIG.
u, descending drive switch Sd, and upper limit stop switch L
Su is configured.

The other end 22b of the release wire 22 having one end 22a connected to the pulley 17 is connected to an arm 9a swinging integrally with the lift arm 9, and the pulley 17 pulls the release wire 22. Next, the pulley 17 is moved in a certain direction by the spring 23 (FIG. 6).
In the U direction).

As shown in FIG. 7, a relay R is interposed in the control circuit of the solenoid operated valve V.
In the excitation circuit of the relay R, an open / close switch Sp that is switched by a PTO clutch lever 24 that interrupts power transmission to the lawn mower 5 and a mode switch Sm are arranged in series.

Further, as shown in FIGS. 2 to 4, a shaft member 14 for connecting the terminal block 14a and the rotary operation lever 16 is provided.
b, a thick disk portion 14c is provided at an intermediate portion, and the thick disk portion 14c and the shaft member 14b from the thick disk portion 14c to the rotary operation lever 16 are connected to the outer fitting cylindrical member 25a. A disk-shaped set dial 25b which is externally fitted and integrated with the externally fitted cylindrical member 25a is disposed between the operation case 13 and the rotation operation lever 16. The shaft member 1 between the disc-shaped set dial 25b and the operation case 13
The outer fitting cylindrical member 25a where the 4b is externally fitted is formed on a screw shaft, and a disk-shaped lock nut 26 is provided in a state of being screwed to the screw shaft. The outer fitting cylinder member 25a, the shaft member 14b, and the thick disk portion 14c are configured to be relatively rotatable around the axis P, but the disk lock nut 26 is closely contacted with the operation case 13. When tightened, the outer fitting cylinder member 25a is moved to the inner wall surface 13a of the operation case 13.
, The outer fitting tube member 25 a is fixed to the operation case 13. Here, the disc-shaped lock nut 26, the screw shaft, the outer fitting tube member 25a, and the inner wall surface 13a constitute a lock mechanism 27. A detent ball 2 elastically urged radially outward by a spring 28 is provided in a concave portion formed in the thick disk portion 14c.
On the other hand, the detent ball 29 is formed at a predetermined position of the outer fitting cylinder member 25a so that the detent ball 29 can be freely engaged and disengaged, thereby forming a detent mechanism 31. Further, the terminal block 14a, the shaft member 14b, and the thick disk 14c constitute a first movable member 14, and the outer fitting cylindrical member 25a and the disc-shaped set dial 25b constitute a third movable member 25. I have.

[Manual Mode] As shown in FIG.
In a state where the mode changeover switch Sm is turned off and set to the manual mode (M), the relay R is in a non-excited state regardless of the switching of the open / close switch Sp, and a state in which energization to the descent drive circuit Dd is possible is obtained. Can be FIG.
(A) shows a state in which the lawn mowing device 5 is stopped at an intermediate position in the elevating range. (A) Ascending operation When the rotation operation lever 16 is rotated by an appropriate amount in the ascending direction U (the counterclockwise direction in FIG. 6) from the state of FIG. 6A, the movable contact of the terminal block 14 rotated in the ascending direction U. 19 contacts the sliding contact 18 to turn on the ascending drive switch Su, and through the ascending drive circuit Du, the ascending solenoid 11
, The lift arm 9 drives the lawn mower 5 upward. Along with this, the other end 22b of the release wire 22 is loosened, and the spring 23 rotates the pulley 17 in the same manner in the ascending direction U by the amount of the looseness, as shown in FIG. When the sliding contact 18 of the printed board 15 rotated in the ascending direction U is relatively separated from the movable contact 19 and the ascending drive switch Su is turned off, the ascending stops. (B) Lowering operation When the rotary operation lever 16 is rotated by an appropriate amount in the lowering direction D (clockwise direction in FIG. 6) from the state shown in FIG. 6A, the movable contact of the terminal block 14 rotated in the lowering direction D 20 comes in contact with the sliding contact 18 to turn on the lowering drive switch Sd, and the lowering solenoid 12 is turned on via the lowering drive circuit Dd.
, The lift arm 9 drives the lawn mower 5 downward. Along with this, the other end 22b of the release wire 22 is pulled, and the pulley 17 is forcibly rotated in the descending direction D by the wire pulling amount against the mainspring 23, and as shown in FIG. The descent stops when the descent drive switch Sd is turned off when the sliding contact 18 of the printed circuit board 15 rotated relative to the movable contact 20 is turned off. In other words, in the manual mode (M), the lawn mower 5 is moved up and down to a height corresponding to the adjustment position of the rotation operation lever 16 and automatically moved up and down by position control. Furthermore, while keeping the cutting height constant,
When the mowing operation is performed, the height of the lawn mowing device 5 with respect to the body of the riding lawn mower is set in advance by the rotation operation lever 16 so that a predetermined mowing height is obtained. Turn the dial 25b to operate the thick disk 14
The detent ball 29 of FIG.
And the disk-shaped lock nut 26 is tightened in this state, so that the outer fitting cylinder member 2 is engaged.
5a and the disc-shaped set dial 25b, that is, the third movable member 25 are fixed to the operation case 13. By doing so, when there is a protrusion such as a pile on the ground during the harvesting operation, the rotation operation lever 16 is simply moved as shown in (a) above without cutting off the PTO clutch lever 24. When the lawn mower 5 is raised, the convex part is avoided by raising the same. After avoiding the convex part, the rotating operation lever 16 is turned downward to operate the detent ball 29 and the concave part 30 at a position where the detent ball 29 and the concave part 30 are engaged. Thus, the lawn mower 5 can be lowered so as to stop at the original mowing height position. As a result, when the lowering operation is performed, the lowering is accurately stopped at the predetermined position without visually checking whether the mowing height of the lawn mower 5 is at the original mowing height position.
Also, even if the cutting height is set arbitrarily, the third setting is performed so that the detent positions of the detent mechanism 31 match in the set state.
Simply by setting the position of the movable member 25 and locking it with the lock mechanism 27, it is possible to cope with the descent to an arbitrary height.

[Automatic Mode] In the automatic mode (A) in which the mode changeover switch Sm is set to ON, the lawn mowing device 5 is moved up and down in accordance with the operation of the PTO clutch lever 24 as follows. (A) PTO clutch disengagement operation When the mode changeover switch Sm is set to the automatic mode (A) and the PTO clutch lever 24 is disengaged in the state shown in FIG. 7, both the open / close switch Sp and the mode changeover switch Sm are turned on. When the relay R is energized, the normally closed contact rb on the lowering drive circuit Dd side opens, and the ascending drive circuit D
The normally open contact ra on the u side is closed, the ascending solenoid 11 is energized regardless of the ascending drive switch Su, and the lift arm 9 drives the lawn mower 5 up. As a result, the other end 22b of the release wire 22 is loosened, and the pulley 17 is also urged and rotated in the ascending direction U by the amount of the looseness.
As shown in (d), when the sliding contact 18 separates from the fixed contact 21 and the upper limit stop switch Su is turned off, the rising stops. In other words, PTO in auto mode (A)
When the clutch lever 24 is turned off, the lawn mowing device 5 rises to the upper limit and stops automatically. (B) PTO clutch engagement operation When the PTO clutch lever 24 is engaged in the state shown in FIG. 6D, the open / close switch Sp is turned off, the excitation of the relay R is cut off, and the lowering drive circuit Dd side is normally closed. contact.
When rb is closed, the normally open contact ra on the ascending drive circuit Du side is opened, the descending solenoid 12 is energized, and the lift arm 9 drives the lawn mower 5 downward from the upper limit position. Accordingly, the other end 22b of the release wire 22 is pulled, and as shown in FIG. 6A, the descent stops when the movable contact 20 separates from the sliding contact 18 and the descent drive switch Sd is turned off. I do. That is, the PTO clutch lever 2
When the switch 4 is turned on, the lawn mower 5 descends to the height set by the rotary operation lever 16 and stops automatically in conjunction with this operation.

Further, as described above, the engine E of the prime mover 2 is operated in conjunction with the engagement operation of the PTO clutch lever 24.
Pulley 2 which constitutes an automatic speed control means for automatically and mechanically changing the speed control mechanism of the engine E to a high output state (see Japanese Patent Application No. 4-34041 previously filed by the present applicant).
One end of a release wire 27 that allows the 6 to be driven to rotate is connected to the PTO lever 24 via a spring 28. As shown in FIG. 5, the end of the outer wire 27a around which the automatic wire speed control means of the release wire 27 is formed is a male screw-formed cylinder so that it can be fixed and held by the fixing nuts 29, 30. The boss 31 is provided.
The length of the cylindrical boss 31 protruding from the fixing portion 29 to the side of the pulley 26 can be arbitrarily adjusted by changing the fixing positions of the lock nuts 30, 30. Further, a drum-shaped stopper member 32 made of metal is fixed to the release wire 27 connected to the pulley 26 at an intermediate position of the inner wire 27b. With this configuration,
When the PTO clutch lever 24 is engaged and operated, the PT
Before the stopper member 32 comes into contact with the end of the cylindrical boss 31 before the O-clutch lever 24 enters the engagement position, the pulley 26 is restricted from rotating only to the position corresponding to the restricted position. The position where the regulation is stopped is set to be the governing position corresponding to the maximum output of the engine E. By the way, the reason for this configuration is that, if there is no stopper member 32, the pulley 26 is driven to rotate in direct association with the swing of the PTO clutch lever 24, and the speed control mechanism is operated accordingly.
There is a risk that the governing mechanism may be unduly operated up to the choke state beyond the preset maximum engine output, but the stopper member 32 and the cylinder boss 31 are connected so as not to exceed the preset maximum engine output. We decided to do this.

[Alternative Embodiment] A suitable means such as an electric motor can be used in place of the hydraulic cylinder 10 as a driving means for raising and lowering the lawn mower 5. Appropriate operation means such as a slide knob can be used instead of the rotation operation lever 16, and these are collectively referred to as an operation tool 16. A slidable member may be used instead of the rotatable terminal block 14a, the shaft member 14b, and the thick disk 14c.
These are collectively referred to as a first movable member 14, and a slidable member may be used instead of the rotatable printed circuit board 15, and they are collectively referred to as a second movable member 15. First
In order to mechanically move the movable member 14 to the operating tool 16, an appropriate transmission means may be provided so that the first movable member 14 slides or rotates as the operating tool 16 rotates or slides. In the embodiment, the sliding contacts corresponding to the movable contacts 19 and 20 and the fixed contact 21 are the common sliding contacts 18 formed by printing.
The sliding contacts 18 corresponding to the 0 and fixed contacts 21 may be provided separately.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is an overall side view showing a riding lawn mower.

FIG. 2 is a schematic explanatory view showing an operation mechanism for operating the raising and lowering of the lawn mower.

FIG. 3 is a side view showing an operation tool, a disc-shaped set dial, and an operation case.

FIG. 4 is a cross-sectional plan view showing a detent mechanism.

FIG. 5 is a side view showing a linkage structure between a PTO clutch lever and a pulley linked to an engine speed governor.

FIG. 6 is a cross-sectional plan view showing a relative positional relationship between a first movable member and a second movable member in the operation mechanism, wherein (a) shows the first and second movable members at a substantially intermediate height position in the elevating operation. FIG. 2B shows that the movable member is set, and FIG.
FIG. 3C illustrates that the movable member is set, and FIG. 3C illustrates that the first and second movable members are set so that the lawn mower is moved to a relatively low position by being lowered. ) Shows that the second movable member is set to operate the lawn mower to the upper limit position.

FIG. 7 is an electric circuit diagram for raising and lowering control of the lawn mower.

[Explanation of symbols]

 Reference Signs List 5 lawn mower 10 actuator 14 first movable member 15 second movable member 16 operating tool 18 sliding contact 19 movable contact 20 movable contact 22 release wire 25 third movable member 27 locking mechanism 31 detent mechanism Sd descent drive switch Su ascent drive switch

Claims (1)

(57) [Claims] The lawn mowing device (5) is connected to an actuator (1).
0) and can be freely lifted and stopped via
First movable member (14) displaced by operating tool (16)
And a release wire (2) to the actuator (10).
2) a second movable member (15) interlockingly connected via the second movable member (15) is disposed so as to be relatively displaceable and opposed to each other;
The movable contact (19) and the sliding contact (18) for constituting the ascending drive switch (Su) for performing the ascending operation are connected to the first contact.
And the second movable members (14) and (15) are separately equipped,
A movable contact (20) and a sliding contact (18) for constituting a descent drive switch (Sd) for lowering the actuator (10) are connected to the first and second movable members (1).
4) and (15), respectively, and the ascending drive switch (Su) is turned on with the displacement operation of the first movable member (14) by the ascending operation of the operating tool (16), so that the actuator is turned on. (10) is raised, and the lifting drive switch (Su) is turned off with the displacement operation of the second movable member (15) in conjunction with the lifting operation of the actuator (10), so that the actuator ( The lifting drive switch (Su) is configured to stop the operation of the first movable member (14) due to the lowering operation of the operating tool (16). (Sd) is turned on to lower the actuator (10),
The lower drive switch (Sd) is turned off with the displacement operation of the second movable member (15) in conjunction with the lowering operation of the actuator (10), and the actuator (10) is stopped. In a lawn mower lifting mechanism of a lawn mower constituting a lowering drive switch (Sd), a detent mechanism (3) is provided with respect to the first movable member (14).
Third movable member (25) that can be set at a fixed position in 1)
Are provided so as to be displaceable, and the third movable member (2
5) A lawn mowing device lifting mechanism of a lawn mower provided with a lock mechanism (27) for fixing the mower at an arbitrary position.