JP5722723B2 - Working vehicle hydraulic system - Google Patents

Description

  According to the present invention, two valves for two hydraulic devices are linked to a single operation lever, and the operation lever is configured to be operable in a second direction intersecting the first direction and the first direction. The present invention relates to a hydraulic device for a work vehicle configured to operate in two directions by operating two valves in a first direction and a second direction.

  Patent Document 1 discloses a lock mechanism that operates a single operation lever in two directions to operate two valves separately in a first direction and a second direction, and locks the operation lever in a neutral position. ing. The locking mechanism includes a concave member that is attached to the base of the operation lever and has a concave portion at the end, and a clamping member that is fitted so as to sandwich the concave member and is provided with a pin that fits into the concave portion.

  When the operation lever is in the neutral position by the above-described locking mechanism, the concave member is fitted into the holding member, and the pin provided in the holding member is fitted into the concave portion formed in the concave member, so that the operation is performed. The lever is locked so as not to move in the first direction and the second direction.

JP 2011-80214 A

  In the lock mechanism of Patent Document 1, a member for locking the operation lever requires a recess member having a recess and a clamping member having a pin fitted to the recess, which increases the number of parts. Further, since the rotation direction of the lock lever and the rotation direction of the clamping member are opposite to each other, it is difficult to recognize whether the operation of the lock lever is a lock operation or a lock release operation.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a hydraulic device for a work vehicle having a simple structure of an operation lever lock mechanism and an operation lever lock mechanism that can easily recognize a lock operation and an unlock operation.

In the first characteristic configuration of the present invention, two valves for two hydraulic devices are linked to a single operating lever, and the operating lever is operated in a second direction that intersects the first direction with the first direction. In the hydraulic device for a work vehicle configured to operate the valves individually, when the operation lever is in a neutral position, the base end portion of the operation lever is moved and operated in accordance with the operation of the operation lever. A lock member configured to be engageable with the base end portion of the operation lever from an orthogonal direction orthogonal to the direction, and capable of rotating about the orthogonal direction, and the lock member rotating about the orthogonal direction The lock member is maintained in the locked state engaged with the base end portion of the operation lever and the unlocked state released from the engagement with the base end portion of the operation lever. a contact portion, said lock Thereby biasing the member toward the proximal end of the operating lever, the urging member the locking member urges the abutment to so that the locking member to the contact portion in the perpendicular direction about the orientation And in the point provided.

[Effect] As in this configuration, when the operating lever is in the neutral position, the base end of the operating lever moves from the direction orthogonal to the two directions in which the base end of the operating lever is moved in accordance with the operation of the operating lever. By providing the lock member that can be engaged, the lock member is directly engaged with the base end portion of the operation lever, and the movement of the base end portion of the operation lever is engaged from the direction orthogonal to the two directions. By being blocked by the lock member, the operation lever can be reliably locked so as not to move.
Further, since the lock member is directly engaged with the base end portion of the operation lever, it can be easily recognized whether the operation of the lock member is a lock operation or a lock release operation.
Further, since the operation lever is locked by directly engaging the lock member with the base end portion of the operation lever, the number of members interposed between the operation lever and the lock member is reduced. The locking mechanism is simple.
As a result, the operation lever can be reliably locked so as not to move at the neutral position, the operability is improved, and the lock mechanism of the operation lever can be simplified.
In addition, when urging the lock member toward the base of the operation lever and urging the lock member in the direction around the axis so that the position of the lock member is maintained, the lock member is provided. It is easy to move to the lock position of the operation lever and also to move to the holding position. As a result, the operability of the lock member is improved. In addition, since one urging member can be used for both urging the lock member to the lock position and urging to the holding position, the number of parts can be reduced.

  According to a second characteristic configuration of the present invention, a cylindrical portion is provided on one of the base end portion and the lock member of the operation lever, and a rod-like portion that can be inserted into an opening formed in the cylindrical portion is provided on the other side. In the point.

[Effect] The base end portion of the operation lever and the lock member need only be engaged so that the operation lever in the neutral position cannot be moved in two directions. For this reason, like this structure, a cylindrical part is provided in one of the base end part of a control lever and a locking member, and the rod-shaped part which can be inserted in the opening formed in a cylindrical part is provided in the other. If comprised in this way, the engaging part of the base end part of a lock member and an operation lever can be comprised simply. Moreover, since the locking operation and unlocking operation of the operation lever can be performed by inserting and removing the rod-shaped portion from the cylindrical portion, it can be easily performed.

It is a side view of a tractor equipped with a front loader. It is a perspective view which shows the operation mechanism and lock mechanism of the operation lever which operate two valves. It is a sectional side view which shows the operation mechanism and lock mechanism of the operation lever which operate two valves. It is a front view which shows the operation mechanism and lock mechanism of the operation lever which operate two valves. It is a perspective view which shows operation operation | movement of the lock member in the lock mechanism of an operation lever. It is a front view which shows the linkage mechanism from the operation mechanism of an operation lever to a valve | bulb. It is a perspective view which shows the operation mechanism and lock mechanism of an operation lever in another embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, a cabin tractor equipped with a front loader R is provided with a four-wheel drive type traveling machine body 3 including a front wheel 1 and a rear wheel 2, a driver seat 4, a steering wheel 5 for steering a front wheel, The cabin C having the operation step 6 and the like is mounted.

  The traveling body 3 includes an engine 7 disposed in a hood 11 at the front of the body, and a gear case 8 and a front frame 12 connected to the engine 7 and a transmission case 9 disposed between the engine 7 and the rear of the body. A sheet metal hollow structure intermediate housing 10 is interposed. In the cabin C, a pair of left and right side brake pedals 17 are arranged in front of the right side of the driving step 6. The rear part of the transmission case 9 is provided with a hydraulically driven lift arm 13 and a rear PTO shaft 14 for taking out power to a working device (not shown) attached to the rear part.

  A front loader R is detachably connected to the front portion of the traveling machine body 3. The hydraulic device that drives the front loader R is equipped as follows.

  A pair of switching valves V are provided in the lateral side portion of the mission case 9 at the lower position on the right side of the driver seat 4, and an operating lever 26 for switching the switching valve V is provided inside the cabin C. It extends upward from the position of the operating mechanism A. The lever operating mechanism A is supported by the mission case 9 and attached to a frame 19 (see FIG. 2) disposed in the front-rear direction along the inside of the rear wheel fender 18. The switching valve V is provided with two three-position switching type valves 23 and 24 arranged in parallel at the front and rear, and is linked to the operation lever 26 as will be described later. (Not shown) can be supplied and discharged with pressure oil.

  The front loader R pivotally connects the boom 32 to the support frame 31 connected and fixed to the front left and right of the traveling machine body 3 so that the boom 32 can swing up and down, and pivotally connects the bucket 33 to the tip of the boom 32 so as to swing the dump truck. A boom cylinder 34 and a bucket cylinder 35, each of which is constituted by a return-acting cylinder, are connected to valves 23 and 24 through oil passages (not shown).

The lever operating mechanism A of the operating lever 26 is configured as follows.
As shown in FIG. 2, a U-shaped support frame 40 in plan view is attached to the upright frame 19. A boss portion 41 in the front-rear direction is supported on the front upper portion of the support frame 40, and the support shaft 42 of the first operation fitting 43 having a U-shaped planar shape rotates around the fulcrum X in the front-rear direction. It is supported so that it can move. The first operation fitting 43 is pivotally supported by a second operation fitting 44 that can turn around a left and right fulcrum Y, and the end of the operation lever 26 is fixed to the upper surface of the second operation fitting 44. . The first operation fitting 43 and the second operation fitting 44 are configured integrally with the operation lever 26 and operate integrally with the operation lever 26 using H located above the second operation fitting 44 as an operation fulcrum. Therefore, the base end portion 26 </ b> A of the operation lever 26 is configured by a portion including the operation fulcrum H, the first operation fitting 43, and the second operation fitting 44.

  As shown in FIGS. 2 to 4, the end portion 43 a of the first operation fitting 43 is extended sideways, and a rod 46 a extending vertically is connected to the end portion 43 a via the linkage fitting 45 a, It is linked to the valve 23. Further, a rod 46 b extending vertically is connected to the rear surface portion of the second operation fitting 44 via a linkage fitting 45 b and linked to the valve 24.

When the operation lever 26 is set to the neutral position N (cross intersection) in the front-rear direction (first direction K) and the left-right direction (second direction L), both valves 23 and 24 are also in the neutral position. When the grip 26B of the operation lever 26 is moved from the neutral position N to the right or left (second direction L), the first operation fitting 43 is rotated around the longitudinal axis X and the rod 46a is moved up and down. Then, the valve 23 for the bucket cylinder 35 is operated.
Further, when the grip 26B of the operation lever 26 is moved forward or backward (first direction K) from the neutral position N, the second operation fitting 44 is rotated around the left and right axis Y and the rod 46b moves up and down. Then, the valve 24 for the boom cylinder 34 is operated.

Next, the lock mechanism B of the operation lever 26 will be described.
The support frame 40 is provided with a lock member 50 for mechanically fixing and holding the operation lever 26 at the neutral position N. A base member 51 is attached to the lower portion of the support frame 40, and a boss portion 52 is erected on the base member 51. The lock member 50 includes a round bar-like lock shaft 53 that is inserted into the boss portion 52 so as to be vertically slidable and rotatable, and a lever portion 54 that is connected and fixed to the outer peripheral surface of the upper portion of the lock shaft 53. An end 53a of the lock shaft 53 is configured to be detachable from an opening of a boss portion 44a that is a cylindrical portion extending downward from the second operation fitting 44. The lock shaft 53 is formed in a round bar shape as a whole, but only the end portion 53a inserted into the opening of the boss portion 44a may be configured as a rod-like portion. On the front side of the support frame 40, a vertical cutout portion 40 a is formed in which the lever portion 54 can be moved.

  At a position facing the lever portion 54 of the frame 19, a lever contact portion 55 having an L shape in front view is provided. The lever portion 54 includes a first lever portion 54A that extends downward from the lock shaft 53 and a second lever portion 54B that extends forward from the end of the first lever portion 54A. A tension spring 56 is installed between the bracket 54C attached to the upper part of the second lever portion 54B and the upper position of the notch 40a of the support frame 40. The upper end of the tension spring 56 is located closer to the frame 19 and is provided in an oblique posture in front view. For this reason, the tension spring 56 biases the lock member 50 in the lock direction (upward), and the direction of the frame 19 (lever contact portion 55) in which the lock member 50 is held at the position of the lever portion 54 of the lock member 50. Energize to.

  When the front loader R is not used, the operation lever 26 is set to the neutral position N and then the lever portion 54 (see FIG. 5) of the lock member 50 below the lever contact portion 55 as shown in FIG. After moving to the right ("A" direction) to remove it from the lever contact portion 55, slide the lock shaft 53 and the lever portion 54 upward ("I" direction). The end portion 53 a of the lock shaft 53 is inserted into the boss portion 44 a of the second operation fitting 44. As a result, the operation lever 26 is mechanically fixed at the neutral position N, and a locked state in which the valves 23 and 24 cannot be operated is set. In the present embodiment, the lock shaft 53 of the lock member 50 is disposed in a direction orthogonal to the two directions (K, L) in which the base end portion 26A of the operation lever 26 is moved in accordance with the operation of the operation lever 26, and the lock An intersection M in two directions (K, L) is located on the extension line of the shaft 53. For this reason, the operation lever 26 locked to the neutral position N is not easily rattled.

  During the operation using the front loader R, the lever portion 54 (shown by a solid line in FIG. 5) of the lock member 50 located in the notch portion 55a of the lever abutting portion 55 is moved in the right direction (the opposite direction of “U”). After being moved and removed from the lever contact portion 55, the lock shaft 53 and the lever portion 54 are slid downward (in the opposite direction to “A”), and the end portion 53 a of the lock shaft 53 is moved to the second operation fitting 44. Pull out completely from the boss 44a. Thereby, the cross operation of the operation lever 26 is permitted, and the valves 23 and 24 can be operated.

  In order to maintain the locked state of the operation lever 26 at the neutral position N, the lever portion 54 is operated to slide the lock shaft 53 upward, the end portion 53a is inserted into the boss portion 44a, and then the lever portion 54 is locked. The second lever part 54B of the lever part 54 is brought into contact with the notch part 55a of the lever contact part 55 by moving in the direction of the lever contact part 55 around the shaft 53. At this time, the tension spring 56 biases the lock shaft 53 in the locking direction (the direction of the base end portion 26 </ b> A of the operation lever 26), and the direction in which the second lever portion 54 </ b> B of the lever portion 54 contacts the lever contact portion 55. Energize to. Thereby, the lever part 54 is hold | maintained in the state contact | abutted to the notch part 55a of the lever contact part 55, and the locked state of the operation lever 26 is maintained.

  On the other hand, in order to maintain the unlocked state of the operation lever 26, the lever portion 54 is operated to slide the lock shaft 53 downward to extract the end portion 53a from the boss portion 44a, and then the lever portion 54 is moved to the lock shaft. The second lever portion 54 </ b> B of the lever portion 54 is positioned below the lever contact portion 55 by moving in the direction of the lever contact portion 55 around 53. At this time, the tension spring 56 biases the second lever portion 54 </ b> B of the lever portion 54 toward the lever contact portion 55. For the urging of the operation lever 26 in the locking direction by the tension spring 56, the lever abutting portion 55 abuts on the second lever portion 54B of the lever portion 54 to prevent the operation lever 26 from moving in the locking direction. Is done. Thereby, the lever part 54 is hold | maintained in the state located under the lever contact part 55, and the unlocking state of the operation lever 26 is maintained.

  As described above, when the operation lever 26 is at the neutral position N, the base end of the operation lever 26 is viewed from the direction orthogonal to the two directions in which the base end portion 26A of the operation lever 26 is moved in accordance with the operation of the operation lever 26. Since the lock member 50 that can be engaged with the portion 26A is provided, the base end portion 26A of the operation lever 26 is moved by the engagement between the base end portion 26A of the operation lever 26 and the lock member 50. It is securely locked so that it cannot move. Since the lock member 50 is engaged with the base end portion 26A of the operation lever 26 from the direction perpendicular to the two directions in which the base end portion 26A of the operation lever 26 is moved, the operation lever 26 is locked. Can be easily recognized as a lock operation or an unlock operation. Since the operation lever 26 is locked by the engagement between the base end portion 26A of the operation lever 26 and the lock member 50, the lock mechanism of the operation lever 26 is simplified.

  As shown in FIG. 6, link members 48a and 48b are connected to the rods 46a and 46b in the horizontal direction via bell cranks 47a and 47b. Link members 48a and 48b are connected to link members 49a and 49b that are formed in an L shape and rotate around the fulcrum S of the bent portion, and the link members 49a and 49b are connected to the valves 23 and 24. Here, the rotation fulcrum P of the bell cranks 47a and 47b is fixed to the cabin C side, and the fulcrum S of the valves 23 and 24 and the link members 49a and 49b is fixed to the body frame side.

By moving the operation lever 26 from the neutral position N to the left or right (second direction L), the first operation fitting 43 is rotated about the longitudinal axis X and the rod 46a moves up and down. The bell crank 47a rotates around the fulcrum P and moves the link member 48a in the left-right direction. By the operation of the link member 48a, the link member 49a rotates around the fulcrum S of the bent portion, and the spool 23a of one valve 23 is operated.
When the operation lever 26 is moved forward or backward (first direction K) from the neutral position N, the second operation fitting 44 is rotated about the left and right axis Y and the rod 46b moves up and down, so that the bell crank 47b rotates around the fulcrum P to move the link member 48b in the left-right direction. By the operation of the link member 48b, the link member 49b is rotated around the fulcrum S of the bent portion, and the spool 24a of the other valve 24 is operated.

  As described above, the vertical movements of the rods 46a and 46b are converted into the horizontal movements of the link members 48a and 48b through the bell cranks 47a and 47b. For this reason, if the cabin C in the state of being rubber-mounted on the machine frame moves up and down with respect to the machine frame, the rods 46a and 46b and the bell cranks 47a and 47b fixed on the cabin C side move up and down. At this time, since the link members 48a and 48b rotate in the vertical direction with the point Q of the connection portion with the link members 49a and 49b as a fulcrum, the link members 49a and 49b are difficult to operate. Thereby, when the cabin C moves up and down with respect to the body frame due to the state of the soil and the like, it is possible to suppress a problem that the valves 23 and 24 are inadvertently operated.

The base end portion 26A of the operation lever 26 has a position that is an operation fulcrum H when the operation lever 26 is operated and a position that is moved in two directions as the operation lever 26 is operated (first direction K and second direction). Position in the direction L). In order to lock the operation lever 26 so as not to move, the lock member 50 is moved and moved in two directions in accordance with the operation of the operation lever 26 at the base end portion 26A of the operation lever 26 (first direction K and second direction). It is necessary to engage at a position in the direction L). Here, the two-way intersection M that is operated to move in accordance with the operation of the operation lever 26 is closer to the operation end (grip) 26B side of the operation lever 26 than the operation fulcrum H when the operation lever 26 is operated. In this case, the engagement position at the base end portion 26A of the operation lever 26 and the lock member 50 must be spaced apart from each other, and the lock member 50 needs to be lengthened. However, as in this configuration, at the base end portion 26A of the operation lever 26, the operation fulcrum H when the operation lever 26 is operated is more than the intersection M in the two directions that is moved in accordance with the operation of the operation lever 26. Is positioned on the operation end (grip) 26B side of the operation lever 26, the engagement position at the base end portion 26A of the operation lever 26 and the lock member 50 can be arranged close to each other, and the lock member 50 can be shortened. Thereby, the lock mechanism B of the operation lever 26 can be comprised compactly.

[Another embodiment]
(1) In the above embodiment, the cylindrical portion (boss portion) 44a is provided on the proximal end portion 26A side of the operation lever 26, and the cylindrical member (boss portion) 44a is inserted into and removed from the lock member 50 side. In this example, the rod-like portion (the end portion of the lock shaft 53) 53a is provided. You may prepare. Further, as shown in FIG. 7, the engagement between the base end portion 26A of the operation lever 26 and the lock member 50 is as follows. (Hole part) 44b. The engagement between the base end portion 26 </ b> A of the operation lever 26 and the lock member 50 can be configured by various engagement convex portions and engagement concave portions. However, if the engaging portion is composed of a cylindrical portion (hole portion) and a rod-like portion, the engagement and disengagement operations can be performed by simply inserting and removing the rod-like portion into the opening of the cylindrical portion. And unlocking can be performed easily.

(2) In the above embodiment, the operation is performed at the base end portion 26A of the operation lever 26 from the intersection M in the two directions (the first direction K and the second direction L) that are moved in accordance with the operation of the operation lever 26. An example is shown in which the operation fulcrum H of the lever 26 is positioned on the operation end (grip) 26B side of the operation lever 26. Instead, the operation end (grip) is at the intersection M in the two directions (the first direction K and the second direction L) that are moved in accordance with the operation of the operation lever 26 rather than the operation fulcrum H of the operation lever 26. ) It may be configured to be located on the 26B side.

(3) In the above embodiment, the extension line of the lock shaft 53 is formed on the operation surface formed in the two directions (first direction K and second direction L) in which the base end portion 26A of the operation lever 26 is moved. Although it is configured to be orthogonal and pass through the intersection point M, the extension line of the lock shaft 53 is formed in two directions (first direction K and second direction L) in which the base end portion 26A of the operation lever 26 is moved. As long as it is orthogonal to the operation surface to be operated, a configuration other than the intersection M may be used.

(4) In the above embodiment, the single biasing member (tensile spring) 56 is used to bias the lock shaft 53 of the lock shaft 53 to the base end portion 26A of the operation lever 26 and to the holding position. However, the urging member may be provided individually. Moreover, you may make it the structure which hold | maintains the position of the lock member 50 using a lock pin etc., without providing an urging member.

  The present invention can be applied to a tractor provided with a snow removal device and a mowing device in addition to the front loader R.

19 Frame 23, 24 Valve 26 Operation lever 26A Base end portion 40 Support frame 43 First operation fitting 44 Second operation fitting 44a Boss portion (tubular portion)
50 Lock member 53 Lock shaft 53a End (bar-shaped part)
54 Lever part 55 Lever contact part (contact part)
56 Tension spring (biasing member)
H Operation fulcrum K 1st direction L 2nd direction N Neutral position

Claims (2)

Two valves for two hydraulic devices are linked to a single operation lever, and the operation lever is operated in a second direction crossing the first direction and the first direction to operate the valves separately. In the work vehicle hydraulic device configured as
When the operating lever is in the neutral position, the base end of the operating lever can be engaged with the base end from the orthogonal direction perpendicular to the two directions in which the base end of the operating lever is moved in accordance with the operation of the operating lever. And a locking member that is rotatable about the orthogonal direction ;
When the lock member rotates and contacts around the orthogonal direction, the lock member is engaged with the base end portion of the operation lever and the base end portion of the operation lever is engaged. A contact portion for maintaining the unlocked state in which is released,
With urges said locking member to said proximal end of said operating lever, with the locking member urges the abutment to so that the locking member to the contact portion in the perpendicular direction about the orientation And a hydraulic device for a work vehicle.   2. The hydraulic pressure of the work vehicle according to claim 1, wherein a cylindrical portion is provided on one of the base end portion and the lock member of the operation lever, and a rod-like portion that can be inserted into an opening formed in the cylindrical portion is provided on the other. apparatus.

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