JP3714825B2 - Body structure of a riding lawn mower - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a riding lawn mower equipped with a mower at the front part of the vehicle body or the lower abdomen of the vehicle body. Specifically, an engine is disposed on the rear side of the pair of left and right drive wheels, and a transmission case is disposed on the front side. The present invention relates to a vehicle body structure of a riding lawn mower having a moor disposed on the front side of the engine and a driver's seat on the front side of the engine.
[0002]
[Prior art]
As this type of riding lawn mower, there is one previously proposed in Japanese Patent Application No. 10-248987. It includes a pair of left and right driving rear wheels, a pair of left and right driven steering wheels, and a mower arranged between the front and rear wheels of the driving rear wheels and the steering front wheels, and an HST for each of the left and right rear wheels. It is constructed with a speed difference steering type in which the front wheel follows the steering depending on the speed difference between the left and right rear wheels, and can turn on the spot by reversing the left and right rear wheels forward and backward. is there.
[0003]
[Problems to be solved by the invention]
The lawn mower of the proposed technique has a structure in which a basic skeleton of a vehicle body frame is configured by a pair of left and right main frames that are long in the front and rear, and a sub frame such as a mounting frame is extended from the main frame as necessary. For example, the upper frame that supports the driver's seat is simply connected to the main frame in a state of being separately arranged on the left and right sides of the main frame. It depends on the strength of the frame.
[0004]
Therefore, in order to ensure sufficient strength and rigidity as a vehicle body frame, the vertical length of the main frame having a long front and rear length must be considerably increased. Due to various restrictions such as the height setting of the vehicle body, it is difficult to provide sufficient strength, and there is room for improvement in terms of vehicle body strength and rigidity.
An object of the present invention is to make it possible to construct a body frame excellent in strength and rigidity without increasing the size of the main frame of the riding lawn mower having the above-described structure by devising the skeleton of the body frame. .
[0005]
[Means for Solving the Problems]
[Configuration of Claim 1]
In a vehicle body structure of a riding-type lawn mower, a first invention has an engine disposed on the rear side of an axle of a pair of left and right drive rear wheels in a side view, and a transmission case disposed on the front side, and the front wheel positioned in front of the transmission case. With a moor between and a driver's seat on the front side of the engine,
The left and right rear frames for mounting and supporting the engine and the transmission case, and the main frame consisting of the front frame for suspending the mower, and the pair of left and right upper frames for supporting the driver's seat are left and right so as to be reinforcing members. the front and rear ends of the respective upper frame, as well as constitute a body frame and rigidly connected to the left and right portions of the main frame, respectively, a pair of left and right upper frames, in front of the engine, and above the transmission case And extending in the front-rear direction and being connected to the left and right main frame portions in a state of straddling the left and right portions of the transmission case in the front-rear direction, respectively .
[0006]
[Effects of the structure of claim 1]
According to the configuration of the first aspect, the pair of left and right upper frames that support the driver's seat provided with a member extending in the front-rear direction at the front position of the engine and at the upper position of the transmission case are respectively provided to the left and right main frame portions. Since the front end and the rear end of the upper frame are rigidly connected to the main frame so as to be reinforcing members, the pair of left and right upper frames become a part of the left and right main frame members to provide strength and rigidity. To improve. In other words, the strength and rigidity of the upper frame is added to the strength and rigidity of the main frame, so that the strength and rigidity of the body frame is largely improved compared to the conventional case, and the layout of various machinery and equipment is free. In order to increase the degree, it is possible to realize sufficient vehicle body strength while forming the main frame with a relatively thin pipe member or a member having a short vertical section.
[0007]
As a result, in the body structure of the riding lawn mower according to any one of claims 1 to 5, a frame component is newly provided by an organic coupling structure that connects the main frame and the upper frame so as to be reinforced. It was possible to improve the strength and rigidity of the body frame without any problems.
In addition, since the front and rear end portions of the upper frame that are separated from the main frame are rigidly connected to the main frame, the bending resistance in the vertical direction is greatly improved, and the vertical bending strength of the body frame is improved. And there is an advantage that the rigidity can be greatly improved.
[0008]
[Configuration of Claim 2]
According to a second invention, in the first invention, the rear frame is composed of a pair of left and right frame members extending in the front-rear direction, the front frame has a front-opening U-shaped plan view shape, and the left and right frame members It is characterized by comprising a pipe material fixed to each front end portion.
[0009]
[Operational effects of the configuration of claim 2]
According to the configuration of the second aspect, it is possible to configure a convenient rear frame that can sufficiently support the heavy load such as the transmission case and the engine by the pair of left and right frame members and sufficiently support the rigidity in the left and right direction. And, since the link mechanism for suspending the moor usually has a pivotal support portion of the lifting arm in a total of four places, front, rear, left and right, by making the front frame a plan view shape of a forward open U-shape, It is suitable for supporting these four pivotal support portions, and can also be suitable for coupling with a pair of left and right frame members. In other words, it was possible to provide a reasonable main frame that is convenient for effectively exhibiting the functions of each part of the lawn mower.
[0010]
[Configuration of Claim 3]
According to a third invention, in the second invention, the upper frame is formed in a U-shape that is open downward in a side view, and the front end of the upper frame is rigidly connected to the front frame and the rear end is rigidly connected to the rear frame. It is characterized by being.
[0011]
[Effects of the structure of claim 3]
According to the configuration of the third aspect, the presence of the upper frame rigidly connected between the main frame and the front frame not only improves the strength and rigidity of the vehicle body frame in the vertical direction, but also the main frame and the front portion. The connection strength with the frame is also reinforced and can be improved. In other words, by contriving the rigid location of the front frame, the connection strength between the main frame and the front frame can be enhanced without providing a new reinforcing member, and a more rational body frame can be provided.
[0012]
[Composition of Claim 4]
According to a fourth invention, in the first to third inventions, the driver's seat is attached to the upper frame so as to be swingable and openable.
[0013]
[Operational effect of the configuration of claim 4]
In the vehicle body structure according to the fourth aspect, since the driver's seat can be swingably opened and closed, the lower part of the driver's seat can be exposed by opening, and the maintainability of that part becomes good. Moreover, since it is a rocking | fluctuating type, the point that there is no possibility of misplacement or loss compared with a detachable type is also preferable.
[0014]
[Configuration of Claim 5]
According to a fifth aspect, in the fourth aspect, the upper frame supports a lock mechanism that maintains the driver's seat in an open posture.
[0015]
[Operational effect of the configuration of claim 5]
According to the configuration of the fifth aspect, since the lock mechanism for keeping the driver's seat in the open posture is provided, it is convenient for maintenance of the mechanical devices arranged under the seat, and the support portion is the upper frame. In addition, the seat can be maintained in an open posture with sufficient strength, which is advantageous in terms of reliability and durability.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 and FIG. 2 show a riding lawn mower in which a mower is mid-mounted in the lower abdomen between the front and rear wheels. Drive rear wheels, 3 is an engine, 4 is a transmission case, 5 is a mower, 6 is a driver's seat, 7 is a lifting link mechanism for hanging the mower 5, and F is a body frame. This lawn mower is provided with an HST (an example of a continuously variable transmission mechanism capable of forward / reverse rotation) 8 for each of the left and right rear wheels 2, 2. It is configured as a speed difference steering type that follows the steering.
[0017]
As shown in FIGS. 7 and 8, the vehicle body frame F is mainly composed of a rear frame 11 that supports the diesel-type, water-cooled engine 3 and the transmission case 4, and a front frame 12 that suspends the mower 5. An upper frame 13 that supports the driver's seat 6 is connected and integrated with the frame f. The rear frame 11 includes a pair of left and right plate frame members 9, 9, a rear end horizontal frame 14 that connects them at the rear end, and an intermediate horizontal frame 15 that connects the front and rear.
[0018]
The front frame 12 is a front end horizontal frame that connects the square pipe member 10 bent to the front end of the left and right plate frame members 9 and 9 and the left and right front end portions thereof, bent in a front-opening U-shape in plan view. 16. The upper frame 13 straddles a pair of left and right rear vertical frames 18 and 18 erected from the plate frame member 9 in the front and rear direction in the vicinity of the rear axle 17, the front end of the plate frame member 9, and the rear end of the square pipe member 10. A pair of left and right front vertical frames 19, 19 erected in a state, a pair of left and right upper front and rear frames 20, 20 connecting the rear vertical frame 18 and the front vertical frame 19, and the upper front and rear frames 20, 20 are connected. The front and rear upper horizontal frames 21 and 22 are provided.
[0019]
A U-shaped plate bracket 53 facing downward in a side view is fixed to the front side of the front end horizontal frame 16. As shown in FIG. 3, the plate bracket 53 is made of a square pipe having front wheels 1 at the left and right ends. The front wheel support frame 54 is supported by a rolling fulcrum P that coincides with the left-right center C of the vehicle body in the left-right direction so that it can swing left and right. The rolling limit of the front wheels 1 and 1 is determined, for example, by contact between the front wheel support frame 54 and the plate bracket upper surface 53a, and can be freely rolled within a predetermined range. The front wheel 1 is configured as a caster wheel that is supported by a front wheel support frame 54 so as to be rotatable about a vertical rotation axis X via a support bracket 55.
[0020]
The engine 3 is supported by anti-vibration support by rubber mounts or the like at four front and rear, left and right brackets 23 projecting inwardly from the left and right plate frame members 9, and a suction type cooling fan 24 is provided at the front side of the engine 3. Before that, a radiator 25 is arranged. The radiator 25 is supported by a pair of left and right brackets 26, 26 projecting inwardly from the left and right plate frame members 9. As shown in FIG. 6, the engine 3 and the transmission case 4 are disposed directly below the radiator 25. An interlocking transmission shaft 27 is disposed in the front-rear direction with a pair of universal joints (not shown). Although the radiator 25 is slightly deviated later in a side view, it is mounted at a position almost directly above the rear axle 17. Immediately before the radiator 25, a dustproof net 30 for preventing foreign matter suction is disposed.
[0021]
Since the radiator 25 is at a higher position than the engine 3 and the projected area in the front-rear direction is larger than the projected area in the front-rear direction of the engine 3, the muffler 28 is disposed on the engine 3. Regardless, the bonnet 29 is set in a shape that is rearwardly narrowed in both a plan view and a side view. In this case, the projected area of the engine 3 is that of the engine alone that does not include auxiliary equipment such as the muffler 28 and the fuel injection device (not shown).
[0022]
As shown in FIGS. 3 to 5, the transmission case 4 has a bifurcated shape in which a rear axle case 32 is bolted to the left and right sides of a center case 31 to which engine power is input.
The center case 31 is configured by integrating the casing portions 31b and 31b of the HSTs 8 and 8 into the left and right sides of the input case portion 31a, respectively, and has a function of distributing the power input to the input shaft 33 to the left and right HSTs 8 and 8. And a PTO shaft 34 provided to project forward for driving the mower 5. The rear axle case 32 transmits the output of the HST 8 to the rear wheel 2 via a gear reduction mechanism (not shown), and the left and right rear axle cases 32, 32 are below the left and right plate frame members 9, 9. The mission case 4 is mounted and supported on the rear frame 11 by bolting at a location straddling the recessed location.
[0023]
As shown in FIGS. 1 and 2, the driver's seat 6 is mounted and supported on the upper frame 13, the fuel tank 35 is located below the rear wheel fender 50 on the left side, and the rear wheel fender 50 is located on the right side. And a pair of left and right speed change levers 37, 37 are installed upright on the front left and right sides of the driver's seat in a forward / backward swing operation type operated by the left and right hands, respectively. A space is provided between the back surface of the backrest 6a of the driver seat 6 and the front surface of the bonnet 29 so that the cooling air for the radiator can be taken in from the front end of the bonnet 29.
[0024]
On the right side of the driver's seat 6, a PTO clutch on / off lever (not shown) that interrupts power to the mower 5 and a hand accelerator lever (not shown) are provided. A lift lever 40 for moving the mower 5 up and down manually is provided on the right of the front of the driver seat 6, and a parking brake lever 41 is provided on the left side. A driving clutch lever (not shown) is disposed on the rear side of the driver seat 6.
[0025]
As shown in FIG. 6, the elevating link mechanism 7 is provided with a pair of left and right arms 44, 45 that are installed on the front frame 12 and the cutting blade housing 43, and interlocks the left and right rear arms 45, 45. A gear interlocking mechanism 47 that spans the rotation shaft 46 and the operation shaft 40 a of the elevating lever 40 is provided. That is, when the lifting lever 40 is swung upward, the mower 5 is lifted, and when the lifting lever 40 is swung downward, the mower 5 is lowered.
[0026]
As shown in FIG. 5, an HST fan 48 for cooling the HST 8 is provided, and a guide plate (an example of a partition member) 49 for sucking the HST fan 48 from below the radiator 25 is provided. is there. That is, an HST fan 48 for the left and right HSTs 8 and 8 is provided on the input shaft 33 of the center case 31, and a guide plate 49 that is lowered from the lower side of the radiator 25 is attached to be sucked from the lower space of the engine 3.
[0027]
That is, the HST 8 cooling air is sucked from the lower side of the engine 3 and the radiator 25 is sucked from the rear of the driver seat 6 and discharged from the rear surface of the hood 29. In addition, the provision of the guide plate 49 prevents mutual interference of exhaust heat.
[0028]
As shown in FIGS. 9 and 10, the driver's seat 6 is supported by the upper frame 13 so as to be swingable and openable at a lateral fulcrum Y provided at the front thereof, and is also lifted and swinged forward to an open posture. A lock mechanism 56 for maintaining the driver's seat 6 is provided. That is, the driver seat 6 is elastically supported by the floor cover 57 via the front pivot point Z and the rear spring 59, and the floor cover 57 is provided on the left and right of the front end portion of the upper frame 13. A fulcrum boss 58, 58 is supported by a lateral fulcrum Y so that it can be opened and closed.
[0029]
The lock mechanism 56 is made of a rail member 60 fixed to the upper frame 13, a support stay 57 a fixed to the back surface of the floor cover 57, and a round bar laid over the rail member 60 and the support stay 57 a. The support rod 61 is substantially Z-shaped. The rail member 60 is formed with a front and rear long guide hole 62 having a lock portion 62a recessed downward at the front end, and in a normal posture (the solid line posture in FIG. 9) with the driver seat 6 closed, A bent portion 61 a at the tip of the support rod 61 is located at the rear end portion of the guide hole 62.
[0030]
When the driver seat 6 is lifted and swung, the support rod 61 moves forward along the guide hole 62, and when the bent portion 61a is dropped and moved to the lock portion 62a, the driver seat 6 is opened (the posture shown in FIG. 10). ) Can be maintained. In the case of closing, the support rod 61 may be slightly lifted and removed from the lock portion 62a.
[0031]
As shown in FIG. 11, a bearing bracket 51 is detachably mounted on the front end of the front frame 12, and a PTO of the center case 31 is driven to drive a front working device (not shown) such as a snowplow instead of the mower. A structure in which the PTO relay shaft 52 linked to the shaft 34 can be supported may be adopted.
[0032]
[Another embodiment]
The positional relationship in which the upper left and right upper and lower frames 10 and 10 of the upper frame 13 are slightly above the plate frame materials 9 and 9 and largely outside to the left and right, and the upper front and rear frame 10 is the plate frame material 9 It may be a positional relationship arranged next to the upper side in the left-right direction. The rigid connection means means for completely integrating by welding as in the embodiment, means for relatively connecting the beams with three or more bolts, one of the rear vertical frame 18 and the front vertical frame 19. Means for welding to the main frame f and connecting the other with one bolt, or the front and rear rear vertical frames 19 and 18 and the main frame f are both connected with two bolts. The member is connected in a state of integrally resisting an external force.
[0033]
The present invention is applied to a front-wheel steering type lawn mower that drives the rear wheels 2 and 2 through a differential device (differential device) and manually steers the front wheels 1 and 1 with a steering operation tool such as a steering handle. It may be applied.
[Brief description of the drawings]
[Fig. 1] Side view of the riding lawn mower [Fig. 2] Plan view of the riding lawn mower [Fig. 3] Plan view showing the configuration of the lower part of the vehicle body [Fig. 4] Front view showing the vicinity of the mission case and the driver seat [Fig. 5] Side view of partially cutout showing the structure of the rear part of the vehicle body [Fig. 6] Enlarged side view of the main part showing the lifting structure of the mower [Fig. 7] Side view of the structure of the vehicle body frame [Fig. Plan view showing the structure [Fig. 9] Side view showing the opening and closing structure of the driver seat and the locking mechanism [Fig. 10] Side view showing the opening posture of the driver seat [Fig. 11] Passenger equipped with a relay PTO shaft instead of the mower Side view of type lawn mower [Explanation of symbols]
Reference Signs List 2 Drive Wheel 3 Engine 4 Mission Case 5 Moore 6 Driver's Seat 9 Frame Member 10 Pipe Material 11 Rear Frame 12 Front Frame 13 Upper Frame 20 Member Extending in the Front-rear Direction 56 Lock Mechanism f Main Frame F Body Frame

Claims (5)

The engine (3) is disposed on the rear side of the axle (17) of the pair of left and right driving rear wheels (2) in a side view, and the transmission case (4) is disposed on the front side. The mower (5) is disposed between the front wheel (1) and the driver (6) on the front side of the engine (3),
A main frame (f) comprising left and right rear frames (11) for mounting and supporting the engine (3) and the transmission case (4), and a front frame (12) for suspending the mower (5); the front and rear ends of the pair of left and right upper frame for supporting the driver's seat (6) (13) and a respective upper frame of the left and right so that the reinforcing members together (13), each said main frame ( The body frame (F) is rigidly connected to the left and right portions of f), and the pair of left and right upper frames (13) are positioned in front of the engine (3) and above the transmission case (4). body structure of a riding lawn mower that is connected to the main frame (f) portions of the left and right left and right portions in a state straddling the longitudinal each of said transmission case extending in the longitudinal direction (4) at the position   The rear frame (11) is composed of a pair of left and right frame members extending in the front-rear direction, and the front frame (12) has a front-opening U-shaped plan view shape, and the left and right frame members respectively. The body structure of the riding lawn mower according to claim 1, wherein the vehicle body structure is made of a pipe material fixed to the front end of the riding lawn.   The upper frame (13) is formed in a substantially downward open U shape in a side view, the front end of the upper frame (13) is the front frame (12), and the rear end is the rear frame (11). The body structure of the riding lawn mower according to claim 2, which is rigidly connected to each other.   The body structure of the riding lawn mower according to any one of claims 1 to 3, wherein the driver's seat (6) is attached to the upper frame (13) so as to be swingable and openable.   The body structure of the riding lawn mower according to claim 4, wherein a lock mechanism (56) for maintaining the driver seat (6) in an open posture is supported by the upper frame (13).

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