JP5432849B2 - Front mower - Google Patents

Description

  The present invention relates to a front mower including a body frame, a moor deck disposed at a front portion of a vehicle body, an elevating cylinder for elevating and lowering the moor deck, an elevating valve for operating and controlling the elevating cylinder, and a transmission case.

  The front mower operates the lifting cylinder by operating the lifting valve to cut the mower deck in parallel with the ground and cut the mower, and lifts the mower deck for movement and maintenance to some extent away from the ground. It can be switched to the non-cutting posture to be in a state (see Patent Document 1).

JP-A-10-117547

When the mower deck is set to the non-harvesting posture, the conventional front mower is not equipped with a mechanism for holding the mower deck. In order to prevent this, the lifting / lowering valve must be frequently operated to lift the mower deck.
The present invention has been made in view of such problems, and an object of the present invention is to ensure that the moor deck is securely held while being lifted from the ground.

A first characteristic configuration of a front mower according to the present invention includes: a fuselage frame; a mower deck disposed at a front portion of a vehicle body; a lift cylinder that lifts and lowers the mower deck; a lift valve that controls the lift cylinder; and a mission case Through an oil passage connecting the elevating valve and the elevating cylinder via a support member in which a valve combining a throttle valve and a check valve is provided, and the valve is fixed to the body frame or the transmission case The operation lever for operating the valve is protruded toward the driver seat from a cover member that is detachable or openable with respect to the floor. .

[Action and effect]
According to this configuration, in normal operation, the throttle lever is operated by operating the operating lever, and the mower deck is moved up and down by operating the lifting cylinder by operating the lifting valve, so that the cutting posture or the non-cutting posture Can be switched to.
On the other hand, for example, when it is desired to hold the mower deck in a state of being lifted upward during traveling, the check lever is operated by operating the operation lever so as to prevent the back flow of oil from the lift cylinder to the lift valve. can do. As a result, the elevating cylinder is not shortened and is reliably held in a state where the mower deck is lifted.

Further, the lowering speed of the mower deck can be adjusted by adjusting the flow rate of oil flowing from the lifting cylinder to the lifting valve by operating the throttle valve with the operation lever.
Furthermore, since the operation lever is protruded from the floor portion on the front side of the driver seat to the driver seat side, the operator can operate the operator lever while sitting on the driver seat, and the operability is good.
Moreover, according to this structure, the maintenance of the valve under it can be easily performed by removing or opening a cover member.

The second characteristic configuration is that the operation lever is disposed at an intermediate position with respect to the left and right footrest positions of the driver.

[Action and effect]
If the operating lever mounting position is set to an intermediate position with respect to the left and right footrest positions of the driver as in this configuration, the driver is most easily operated when the driver leans forward to operate the operating lever. The operation lever does not get in the way when the driver gets on and off.

According to a third characteristic configuration, the operation lever is configured by a rotating shaft member capable of adjusting an opening of the throttle valve, and the rotating shaft member is provided so as to protrude upward through the floor portion. There is in point.

[Action and effect]
If the operating lever is configured with a rotating shaft member provided so as to protrude upward through the floor as in this configuration, the opening of the throttle valve is adjusted by rotating the rotating shaft member around its axis. Operation is easy.
According to a fourth feature configuration, the valve includes a case, and a spring, a poppet, and a bearing portion are housed in this order from below in the case, and the rotating shaft member is disposed in the bearing portion with an inner periphery of the bearing portion. It is arranged in a screwed state, the rotary shaft member can be moved up and down by rotating, the upper end of the poppet and the lower end of the rotary shaft member are in contact, and by rotating the rotary shaft member, The poppet is configured to move up and down to adjust the opening of the throttle valve.

It is a whole side view of a front mower. It is a whole top view of a front mower. It is a top view of the lower side of a floor part. It is a vertical side view of the vicinity of the floor. It is a longitudinal cross-sectional view of a valve. It is a hydraulic circuit diagram which hydraulically drives the elevating cylinder.

Embodiment
An embodiment of the front mower according to the present invention will be described based on FIGS.
As shown in FIGS. 1 to 3, the front mower includes a body frame 1, a mower deck 2 disposed at the front of the vehicle body, a single-acting lift cylinder 3 that moves the mower deck 2 up and down, a driver seat 4, A driving front wheel 5, a steering rear wheel 6, a driving part 7, a floor step 8 (floor part), and a mission case 9 are provided.

  The mower deck 2 is supported through a pair of left and right support frames 10 pivotally supported on the front portion of the body frame 1 and a lift arm 11 driven by the lift cylinder 3.

  As shown in FIG. 1, when mowing work is performed with the mower deck 2 placed close to the ground in parallel, if the elevating cylinder 3 is shortened, the support frame 10 is moved downward and the mower deck 2 is lowered. The ground ring 12 comes into contact with the ground, and the mower deck 2 is in the cutting position.

  Although not shown, when the mower deck 2 is lifted and moved away from the ground for movement and maintenance, when the elevating cylinder 3 is extended, the support frame 10 is lifted and swung to raise the mower deck 2, and the mower deck 2 is grounded. The wheel 12 moves away from the ground, and the mower deck 2 assumes a non-reaching posture.

  As shown in FIG. 3, the elevating cylinder 3 is arranged on the right side of the mission case 9, and the elevating valve 13 for controlling the operation of the elevating cylinder 3 is arranged behind the mission case 9. The elevating cylinder 3 and the elevating valve 13 are connected via a first hydraulic hose 14, a second hydraulic hose 15, and a valve 16.

  The valve 16 is welded and fixed to the tip of a fixed piece 26a of a stay 26 (support member). The stay 26 includes a fixed piece 26a and a base portion 26b. The fixed piece 26 a is provided at the left end of the base portion 26 b so as to protrude forward of the vehicle body, and the base portion 26 b is fixed with bolts 27 so as to extend in the left-right direction on the front surface of the transmission case 9. The fixing position of the stay 26 is not limited to this position, and other positions (for example, the upper surface side) of the mission case 9 and appropriate positions (for example, the right or left body frame 1) of the body frame 1 are not limited. May be fixed to the vertical plate portion).

  As shown in FIGS. 2 and 4, the valve 16 is disposed below the floor step 8 (cover member 37) on the front side of the driver's seat 4.

  As shown in FIG. 5, the valve 16 includes a case 17, a spring 18, a poppet 19, a bearing portion 20, and a rotating shaft member 21 (operation lever).

  In the case 17, a spring 18, a poppet 19, and a bearing portion 20 are accommodated in order from the bottom, and the rotating shaft member 21 is inserted and disposed in the bearing portion 20. The spring 18 and the lower end of the poppet 19 are in contact with each other, and the upper end of the poppet 19 and the lower end of the rotating shaft member 21 are in contact with each other.

  The poppet 19 is biased upward by a spring 18. A male screw portion 22 is formed on the outer peripheral surface of the tip portion of the rotary shaft member 21, and a female screw portion 23 is formed on the inner peripheral surface of the bearing portion 20, and the rotary shaft member 21 is rotated about its axis. Can be moved in the vertical direction. A T-shaped or L-shaped operation portion 21 a is formed at the upper end portion of the rotating shaft member 21.

  The gap between the tip 20a of the bearing portion 20 and the poppet 19 can be increased as the rotary shaft member 21 is moved downward, and conversely, the tip 20a of the bearing portion 20 is moved as the rotary shaft member 21 is moved upward. The oil passage can be closed by reducing the gap between the poppet 19 and finally bringing the poppet 19 into contact with the tip 20 a of the bearing portion 20 by the biasing force of the spring 18. When the poppet 19 is in contact with the tip 20a of the bearing portion 20, the longitudinal direction of the operation portion 21a of the rotary shaft member 21 is in the front-rear direction.

  That is, the poppet 19 and the bearing portion 20 function as a check valve and a variable throttle valve. By operating the rotary shaft member 21, the backflow of oil can be prevented as a check valve, and the oil can be used as a variable throttle valve. The flow rate of can be adjusted.

  A first hose connection portion 24 and a second hose connection portion 25 are provided on the lateral side surface of the case 17 in the vertical direction. As shown in FIG. 3, the 1st hose connection part 24 has faced the back side of the vehicle body, and the 2nd hose connection part 25 has faced the diagonally right rear direction of the vehicle body.

  As shown in FIGS. 3 and 4, the lift valve 13 and the first hose connection portion 24 are connected via the first hydraulic hose 14, and the lift cylinder 3 and the second hose connection portion 25 are connected to the second hydraulic hose 15. Connected through. Specifically, as shown in FIG. 3, one end of the first hydraulic hose 14 is connected to the first hose connection portion 24, and the other end is connected to the lift valve 13 at the left rear of the transmission case 9. Further, one end of the second hydraulic hose 15 is coupled to the second hose connection portion 25, and the other end is coupled to the elevating cylinder 3 on the right side of the transmission case 9.

  As shown in FIG. 3, the first hydraulic hose 14 and the second hydraulic hose 15 having the same length can be used by disposing the valve 16 at a position slightly deviated to the left of the left and right center of the vehicle body. It is configured. Therefore, it is not necessary to distinguish and assemble these hydraulic hoses.

  As shown in FIG. 6, the elevating valve 13 includes a main spool 28 and a relief valve 29, and a hydrostatic continuously variable transmission 30 (hereinafter referred to as HST 30) and a transmission case 9 are disposed in the oil passage. It is connected.

  The HST 30 includes a variable displacement hydraulic pump 31, a hydraulic motor 32, a charge pump 33, a relief valve 34, and the like. The oil in the mission case 9 is charged by the charge oil from the charge pump 33 through the lift valve 13. In addition to being sent to the lift cylinder 3, it is sent to the PTO clutch 36 via the operation valve 35 for turning on and off the PTO clutch 36.

  Although not shown in the drawings, during normal operation, the rotary shaft member 21 (see FIG. 5) is rotated about its axis and moved downward to move the poppet 19 (see FIG. 5) of the valve 16 and the bearing portion 20 to each other. A gap is provided between the tip 20a (see FIG. 5). Thereby, oil can go back and forth between the 1st hose connection part 24 (refer to Drawing 5) and the 2nd hose connection part 25 (refer to Drawing 5) (state where valve 16 is operated as a throttle valve). .

  When the mower deck 2 is lifted to the non-cutting posture separated from the ground, a position lever (not shown) is operated to switch the main spool 28 from the neutral position 28N shown in FIG. 6 to the raised position 28U.

  Then, the oil sent from the charge pump 33 passes through the valve 16 provided in the oil passage (first and second hydraulic hoses 14 and 15 in FIG. 3) connecting the lift valve 13 and the lift cylinder 3 to the lift cylinder. As a result of the elevating cylinder 3 being extended, the mower deck 2 (see FIG. 1) is driven up.

  Further, when mowing work is performed with the mower deck 2 close to the ground, a position lever (not shown) is operated to switch the main spool 28 from the neutral position 28N shown in FIG. 6 to the lowered position 28D.

  Then, the oil in the lifting cylinder 3 can be drained to the transmission case 9 via the valve 16 and the lifting valve 13, the lifting cylinder 3 is shortened by the weight of the mower deck 2, and the mower deck 2 is lowered by its own weight. To do. At this time, the rotary shaft member 21 (see FIG. 5) of the valve 16 is rotated about its axis and moved in the vertical direction to adjust the size of the gap between the tip 20a of the bearing portion 20 and the poppet 19. Thus, it is possible to adjust the flow rate of oil flowing from the lifting cylinder 3 to the lifting valve 13. Accordingly, the lowering speed of the mower deck 2 can be adjusted by causing the valve 16 to function as a variable throttle valve.

On the other hand, for example, when it is desired to hold the mower deck 2 in the state of being lifted upward during traveling, the neutral position shown in FIG. The main spool 28 is switched from 28N to the raised position 28U, and the mower deck 2 is lifted.

  Then, as shown in FIG. 5, the rotary shaft member 21 is rotated around its axis and moved upward, so that the poppet 19 is brought into contact with the tip 20a of the bearing portion 20 by the urging force of the spring 18, thereby Block the passage (the state in which the valve 16 is operated as a check valve).

  As a result, even if a back flow of oil from the lift cylinder 3 to the lift valve 13 occurs, the function of the check valve is exhibited by the poppet 19 and the bearing portion 20 of the valve 16. Oil backflow is prevented. Therefore, the elevating cylinder 3 is not shortened and is reliably held in a state where the moor deck 2 is lifted.

  As shown in FIGS. 2 and 4, a cover member 37 that is pivotable around a fulcrum P and that can be opened and closed is provided at the left and right intermediate portion of the floor step 8. The cover member 37 may be configured to be detachable from the floor step 8. If it is comprised in this way, the maintenance of the valve 16 under it can be easily performed by opening the cover member 37. FIG. Further, as shown in FIG. 3, in the present embodiment, the valve 16 is arranged at a position slightly deviated to the left of the left and right center of the vehicle body, so that the valve 16 is provided at the left and right center of the vehicle body. Thus, it is easy for an operator to perform maintenance when the valve 16 is maintained on the left side of the vehicle body.

  As shown in FIG. 4, the rotary shaft member 21 passes through a long hole 38 formed in the cover member 37 in the front-rear direction and protrudes toward the driver seat 4 (above the upper surface of the cover member 37). . When the opening and closing operation of the cover member 37 is performed by making the hole penetrating the rotation shaft member 21 into a long hole 38 long in the front-rear direction, the cover member 37, the rotation shaft member 21, and the rotation shaft member 21 operation portion 21 a It is comprised so that it may become difficult to mutually interfere.

  As shown in FIG. 2, the long hole 38 is provided at an intermediate position with respect to the left and right footrest positions 39, 39 of the driver. With this configuration, the driver is most easily operated when the upper body is tilted forward to operate the rotating shaft member 21, and the rotating shaft member 21 does not get in the way when the driver gets on and off. Furthermore, since the rotating shaft member 21 is disposed slightly to the left of the left and right center of the vehicle body, the driver can easily operate the rotating shaft member 21 with the left hand while operating the handle 40 with the right hand.

[Another embodiment]
(1) As a valve of the above-mentioned embodiment, you may use what equips each with a throttle valve and a non-return valve. In this case, the throttle valve and the check valve may be connected in a parallel circuit by an internal circuit or an external pipe, and an operation lever that operates only the opening degree of the throttle valve may be provided.

  (2) The throttle valve of the above-described embodiment is not limited to a variable throttle valve, and a fixed throttle valve whose opening degree cannot be adjusted may be provided. In this case, you may comprise so that a fixed throttle valve can be operated by a control lever in a fully closed state and a predetermined opening degree state.

  (3) The valve according to the above-described embodiment may be disposed at the center of the left and right sides of the vehicle body, or may be disposed at a position slightly deviated to the right of the center of the left and right sides of the vehicle body.

  As described above, the present invention is useful for a front mount type riding lawn mower.

1 Airframe Frame 2 Moore Deck 3 Lifting Cylinder 4 Driver's Seat 8 Floor Step (Floor)
9 Mission case 13 Lift valve 16 Valve 21 Rotating shaft member (control lever)
26 Stay (support member)
37 Cover member 39 Footrest position

Claims (4)

A fuselage frame, a mower deck disposed at the front of the vehicle body, a lift cylinder that lifts and lowers the mower deck, a lift valve that controls the lift cylinder, and a mission case,
In the oil passage connecting the elevating valve and the elevating cylinder, a valve combining a throttle valve and a check valve is provided,
Through the support member fixed to the fuselage frame or the transmission case, the valve is disposed below the floor portion on the front side of the driver seat;
A front mower in which an operation lever for operating the valve protrudes toward the driver's seat from a cover member that is attachable / detachable to / from the floor . The front mower according to claim 1 , wherein the operation lever is disposed at an intermediate position with respect to the left and right footrest positions of the driver. The operating lever is constituted by the rotary shaft member adjustable the degree of opening of the throttle valve, the rotating shaft member is the cover Claim member through the are arranged so as to project upward 1 or 2 Front moor as described in. The valve includes a case, and a spring, a poppet, and a bearing portion are housed in this order from below in the case, and the rotary shaft member is disposed in the bearing portion in a state of being screwed with the inner periphery of the bearing portion. The rotary shaft member is movable up and down by rotating, and the upper end of the poppet and the lower end of the rotary shaft member are in contact with each other,
The front mower according to claim 3 , wherein the poppet is configured to move up and down to adjust the opening of the throttle valve by rotating the rotating shaft member .

Images