JP2521195Y2 - Agricultural tractor - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an agricultural tractor characterized by a PTO gear shifting operation structure.

[Conventional technology]

Generally, the PTO gear shift lever of an agricultural tractor is provided on the side of the driving unit along with the main gear shift lever and sub gear shift lever for traveling, and other 2WD / 4WD switching levers.

[Problems to be solved by the device]

However, in recent years, there has been an increasing demand for multi-speed shifting and reverse shifting of PTO output in agricultural tractors, and the operating space of the PTO shifting lever tends to increase accordingly.

In this case, the operation frequency of the PTO speed change lever is lower than that of various operation levers of the traveling system, so the operation lever of the traveling system is preferentially installed in a place where it is easy to operate.
The O gear shift lever tends to be installed in a place that is difficult to operate, and there was room for improvement. It is often difficult to operate the parts that are difficult to operate with the PTO gear shifting, and the linking mechanism tends to be complicated with many parts.

The present invention focuses on such a situation, and aims to improve the operability of the PTO gear shifting structure and to make it mechanically simple.

[Means for solving the problem]

In order to achieve the above object, the present invention forms a clutch chamber in the front half of a clutch housing directly connected to an engine and a shift chamber in the rear half of the clutch housing for accommodating a main transmission mechanism and a PTO transmission mechanism of a traveling system in a left-right parallel manner. However, the shift fork of the PTO speed change mechanism and the pivotal support of the operation arm that are selectively engaged with the engaging portion of the shift fork of the PTO transmission mechanism in the upper space near the corner in the cross section of the clutch housing when viewed in the front-rear direction. The shaft support part is configured with a ball fulcrum, and each engaging part is arranged on an arc around the ball fulcrum of the shaft support part, and the operation arm is linked to the PTO gear shift lever located on the upper surface of the clutch housing. It is characterized by being present.

[Action]

According to the above configuration, the shift fork, the operation arm, and the like, which are the operation portion for the PTO speed change mechanism, can be arranged by utilizing the empty space existing in the corner portion of the space inside the clutch housing, so that the cross-sectional shape of the clutch housing is compact. Can be formed into.

Since the operating arm is directly supported by the clutch housing, the PTO linked to the operating arm is interlocked.
The gear shift lever can be located on the upper rear surface of the clutch housing, that is, in front of the feet of the driving unit. This position corresponds to the vicinity of the lower part of the control panel, where special operation levers have not been installed in the past, and it becomes possible to operate the PTO gear shift lever capable of multi-speed shifting in front of the driver's feet without difficulty.

[Effect of device]

As a result, it is possible to easily install various operating levers of the traveling system that are frequently operated in a wide area on the side of the driving part, and it is also possible to operate the PTO gear shifting lever that can shift multiple steps without difficulty, improving operability. In addition, the PTO gear shifting operation part can be made compact by using the space inside the clutch housing effectively, and a simple structure with a small number of parts for the linkage structure can be realized, improving productivity and reducing costs. It is also effective in trying.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an agricultural tractor according to the present invention. This agricultural tractor is configured as a monobody type in which an engine (1), a clutch housing (2), an intermediate transmission case (3), and a mission case (4) are connected in this order from the front part to the rear part of the machine body, A driver's seat (5) is provided above the mission case (4), and a hydraulic lift arm (6) for raising and lowering the work device and a PTO shaft (7) for driving the work device are provided at the rear of the mission case (4). There is.

Next, the transmission structure of the traveling system and the PTO system will be described with reference to FIG.

The inside of the clutch housing (2) is divided into front and rear via a bearing front wall (2a), and the first half of the clutch chamber (A).
Is equipped with a dry single plate main clutch (8),
The main transmission mechanism (9) for the traveling system and the PTO in the latter half of the transmission chamber (B)
The transmission mechanism (10) and the transmission mechanism (10) are arranged side by side in a horizontal direction (FIG. 1 is a development view, and therefore is shown in a state in which they are vertically arranged in parallel).

Then, the forward / reverse switching mechanism (11) for the traveling system is incorporated in the intermediate transmission case (3), and the auxiliary transmission mechanism (12) for the traveling system and the super-reduction mechanism (13) are provided in front of the transmission case (4). However, the rear part of the mission case (4) is equipped with a differential mechanism (14) for driving rear wheels.

A main shaft (15) connected to the main latch (8) is provided near the upper center of the left and right of the clutch housing (2), and a counter shaft (16) geared to this is provided below the main shaft (15). Then, the transmission shaft (17) for the traveling system and the transmission shaft (18) for the PTO system are arranged on both sides of the counter shaft (16) (see FIG. 3).

The first to fourth gears (G ₁ ), (G ₂ ), (G ₃ ), and (G ₄ ) are integrally formed on the counter shaft (16) from the rear to the front, and the traveling system transmission shaft (17) Corresponding to these gears (G ₁ ) to (G ₄ ), the first speed gear (G ₅ ), the first shift gear (G ₆ ) as the second speed gear, the third speed gear (G ₇ ) and the third speed gear (G ₇ ). the second shift gear (G ₉₎ is respectively provided for integrating the fourth speed gear (G _8), the first speed in the right shift of the first shift gear (G ₆₎ is, the second speed in leftward shift obtained In addition, the main transmission mechanism (9) is configured so that the third speed can be obtained by the right shift of the second shift gear (G ₉ ) and the fourth speed can be obtained by the left shift.

Further, the PTO system speed change shaft (18) also has the first main speed change mechanism (9).
Speed gear (G _5), the first shift gear (G _6), second shift gear (G ₉₎
1st speed gear (G ₁₀ ), 1st shift gear (G ₁₁ ) as 2nd speed gear, 3rd speed gear (G ₁₂ ) and 4th speed gear with exactly the same specifications as
A second shift gear (G ₁₄ ) integrated with (G ₁₃ ) is provided, and a third shift gear (G ₁₅ ) that constantly meshes with the first shift gear (G ₁₁ ) is provided on the reverse rotation shaft (19). By shifting the first shift gear (G ₁₁ ) and the second shift gear (G ₁₄ ) to the left or right, the transmission shaft (18) can be shifted in four forward rotations, and the third shift gear (G ₁₅ ) is shifted to the left. Reverse gear shifting is also possible by engaging the second shift gear (G ₂ ) of the counter shaft (16).

The PTO gear shifting shaft (18) is the intermediate transmission shaft (20), (21).
PTO shaft (7) at the rear of the mission case (2)
Is linked to.

Next, the main transmission mechanism (9) and the PTO transmission mechanism (10)
The operation structure of will be described.

As shown in FIG. 3, engaged with the spindle (22) of the first shift fork (21) and the second shift gear (G ₉ ) engaged with the first shift gear (G ₆ ) of the main transmission mechanism (9). The support shaft 24 of the second shift fork (23) is supported so as to be slidable back and forth between the bearing front wall (2a) of the clutch housing (2) and the bearing rear wall (25) additionally attached to the rear end of the clutch housing. , An operating shaft (27) having an operating arm (26) selectively engaged with engaging recesses (21a), (23a) formed in the bases of the shift forks (21), (23) has a clutch housing (2). ) Is attached to a bracket (28) attached to the left outer side surface of the bracket so as to be slidable forward and backward and rotatable. And the fifth
As shown in the figure, this operation shaft (27) is extended to the rear of the fuselage, and is attached to the left side of the transmission case (4) via a ball fulcrum (29) so as to be swingable back and forth and left and right ( 3
The projection (27a) attached to the rear end of the operating shaft (27) is engaged with the lower end tubular portion (30a) of (0), and the operating shaft (27) is rotated by the left and right swing of the main speed change lever (30). By moving the operating arm (26), the shift forks (21) and (23) are selected, and the main shaft lever (30) is swung back and forth to move the operating shaft (2
7) Push back and forth to select the shift fork (2
It is configured to shift 1) or (23) back and forth.
The rear wall (25) of the bearing has a restraining ball (31) for preventing simultaneous double speeding operation of the support shafts (22), (24) and a spring ball (32) for speed change detent. ) Is incorporated.

As shown in FIG. 3, engage the shaft (34), second shift gear (G ₁₄₎ of the first shift fork engaged with the first shift gear of the PTO transmission mechanism (10) (G ₁₁₎ (33) The support shaft (36) of the second shift fork (35) and the support shaft (3) of the third shift fork (37) engaged with the reverse third shift gear (G ₁₅ ).
8) and the bearing front wall (2a) and the bearing rear wall (25) are slidably supported in the front-rear direction, and are selectively engaged with the bases of the shift forks (33), (35), (37). The arm (39) is supported so as to be able to swing back and forth and left and right via a ball fulcrum (41) of a fulcrum bracket (40) mounted on the upper right side of the clutch housing (2). The operation arm (39) penetrates the ball fulcrum (41) and extends upward to form a PTO gear shift lever (43) located near the lower part of the control panel (42) in front of the driver's seat (5). Has been done.

That is, the shift forks (33), (35), (of the PTO speed change mechanism (10) are located in the inner space of the clutch housing (2), which is an upper position near the right corner in the cross section of the clutch housing (2) when viewed in the front-rear direction. 37) and a ball fulcrum (41) which is a pivotal support of the operation arm (39) selectively engaged with the engaging parts (33a), (35a), (37a), and the engaging parts are arranged. (33a), (35a), (37a) are arranged on an arc around the center of swing with respect to the ball fulcrum (41), and the operation arm () is attached to the PTO speed change lever (43) located on the upper surface of the clutch housing (2). 39) is linked and linked.

Therefore, by swinging the PTO speed change lever (43) back and forth in the middle of the left and right, the forward first speed and the second speed are obtained,
In addition, by tilting the PTO speed change lever (43) to the left and swinging it back and forth, the third and fourth speeds of forward rotation can be obtained, and further, tilt the PTO speed change lever (43) to the right and shake it backward. Reversal is obtained by moving.

Further, the respective support shafts (34), (36), (38) are prevented from being simultaneously operated by the check ball (44) group incorporated in the bearing rear wall (25), and at the same time, the spring ball (45). Each shift position is ensured by the group.

The speed change lever (46) of the forward movement switching mechanism (11) is provided on the left side of the steering post (47), and the operation levers of the auxiliary speed change mechanism (12) and the super speed reduction mechanism (13) are not shown. It is provided near the speed change lever (30).

It should be noted that reference numerals are added to the claims of the utility model for convenience of comparison with the drawings, but the present invention is not limited to the structure of the accompanying drawings by the entry.

[Brief description of drawings]

The drawings show an embodiment of an agricultural tractor according to the present invention.
Fig. 1 is an overall side view of an agricultural tractor, Fig. 2 is a developed cross-sectional view of a transmission structure, Fig. 3 is a rear view showing shift operating parts of a main transmission mechanism and a PTO transmission mechanism, and Fig. 4 is a rear view of a clutch housing. FIG. 5 is a side view of the main shift operation structure. (1) …… Engine, (2) …… Clutch housing,
(9) …… Main transmission, (10) …… PTO transmission, (3
3), (35), (37) …… Shift fork, (33a),
(35a), (37a) ... engaging part, (39) ... operation arm,
(41) …… Shaft support, (43) …… PTO gear shift lever.

Claims (1)

(57) [Scope of utility model registration request] 1. A clutch housing (2) directly connected to an engine (1) has a clutch chamber (A) in a front half thereof, and a main transmission mechanism (9) and a PTO transmission mechanism (10) of a traveling system in a left and right side thereof in a rear half thereof. The transmission chambers (B) to be housed in the state are respectively formed, and the PTO transmission mechanism () is provided in the inner space of the clutch housing (2) which is an upper position near a corner in the cross section of the clutch housing (2) when viewed in the front-rear direction. 10) shift forks (33), (35), (37) and their engaging portions (33)
a), (35a), (37a) alternative operation arm (3
9) the shaft support portion (41) is arranged, the shaft support portion (41) is constituted by a spherical fulcrum, and the engaging portions (33a), (35
a) and (37a) are arranged on an arc around the fulcrum of the shaft support (41), and the operation arm (39) is attached to the PTO gear shift lever (43) located on the upper surface of the clutch housing (2). An agricultural tractor that is linked and linked.