JP4116892B2 - Tillage shaft seal structure of rotary tiller - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tilling shaft seal structure of a rotary tiller provided in a tiller.
[0002]
[Prior art]
A conventional tillage shaft seal structure of a tiller is a structure in which a cover that prevents foreign matter from entering a seal attached to the tiller shaft is disposed in front of the oil seal (see, for example, Patent Document 1).
[0003]
[Patent Document 1]
Japanese Utility Model Publication No. 57-102902 (page 3-4, Fig. 2)
[0004]
Patent Document 1 will be described in detail with reference to the drawings.
FIG. 8 is an explanatory view of a tilling claw shaft support structure of a conventional rotary tilling device (a copy of FIG. 2 of Patent Document 1).
In the conventional tillage claw shaft support structure, the tillage claw shaft 4 is attached to and supported by the support member 2 (the reference sign is the same as that described in the same publication. The same applies hereinafter) via the ball bearing 9 and the seal member 5. By arranging the cover 1 attached to the tillage claw shaft 4 within the cylindrical part end surface 12 of the cylindrical part 2a of the member 2, the waste 1 or the like is prevented from being wound around the cover 1.
[0005]
[Problems to be solved by the invention]
The structure of FIG. 8 described above makes it difficult for wrapping and the like to wrap around the end surface 11 of the cover 1, but when the straw or grass reaches the outer cylindrical portion 1a of the cover 1, the movement on the outer cylindrical portion 1a is easy. It is easy to invade and the frequency of removing straw and grass is increased, which takes time.
[0006]
Accordingly, an object of the present invention is to suppress the intrusion of grass and soil toward the sealing member provided between the support case and the tilling shaft, thereby increasing the durability of the sealing member. It is to provide a sealing structure.
[0007]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the first aspect of the present invention provides a support case in which a tilling shaft is rotatably supported via a bearing, and a sealing member that prevents foreign matters directed to the bearing is disposed outside the bearing. A rotary shaft tiller shaft sealing structure for a rotary tiller in which a seal cover means for reducing foreign matter directed to the seal member is interposed between the tillage shaft and the support case outside the seal member. The cover means includes a rotating cover member attached to the tilling shaft and a fixed cover member attached to the support case. The rotating cover member has a female conical portion whose diameter increases toward the support case. And a male conical portion surrounding the female conical portion.
[0008]
The female conical portion whose diameter increases toward the support case becomes a barrier to the progress of the grass that gradually decreases in diameter toward the support case, and foreign substances such as grass and soil wrapped around the grass are less likely to enter. Therefore, it is possible to suppress the intrusion of grass or soil toward the seal member and improve the durability of the seal member.
[0009]
According to claim 2, when turning the tiller axis for tilling, and characterized by forming a helical groove foreign matter reaches the female cone progresses from enlarged side to diametrically contracted on the outer surface of the female cone To do.
[0010]
When plowing is performed, the female cone rotates, and the spiral groove also rotates. As a result, it is possible to promote the discharge of grass or soil that has reached the outer surface of the female cone by the rotating spiral groove. Therefore, the durability of the seal member can be further improved.
[0011]
According to a third aspect of the present invention, the spiral groove is characterized in that the peak portion is formed at an acute angle.
The sharp mountain top can cut the grass that winds around the female cone and tightens it, and the sharp mountain top can smooth out the discharge of grass and soil that has reached the female cone, Suppress.
[0012]
According to a fourth aspect of the present invention, an interval between the female cone portion and the male cone portion is narrowed in a direction away from the seal member.
The grass returned toward the direction away from the seal member by the rotation of the spiral groove formed on the outer surface of the female cone is compressed and cut further in a narrow space. As a result, the wrapping of grass is further suppressed and the invasion of grass is suppressed.
[0013]
According to a fifth aspect of the present invention, the female cone portion is characterized in that an edge portion formed by the outer surface and the end surface is formed at an acute angle.
By making the edge part into an acute shape, a cutting edge is obtained. A sharp edge can cut the grass more reliably. That is, the grass that could not be cut at the top of the mountain can be cut at the end face, further suppressing the winding of the grass and suppressing the invasion of the grass.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a perspective view of a walking rotary tiller that employs a tillage shaft seal structure according to the present invention. "Left", "right", "upper", and "lower" in the upper right of the figure are directions viewed from the operator, "front" is the forward side, and "rear" is the opposite side.
[0015]
The walking-type rotary tiller 10 (hereinafter simply referred to as “cultivator 10”) includes a left and right traveling wheels 13 and 14 (refer to FIG. 3) and an engine 11 serving as a drive source via a power transmission device 12 and these components. Power is transmitted to the left and right rotary tillers 15 and 16 disposed in front of the traveling wheels 13 and 14, and a work device such as a vertical device 17 (see FIG. 2) is connected to the rear portion of the power transmission device 12. While plowing the field with the rotary tillers 15 and 16, for example, the tiller 17 raises the straw.
[0016]
FIG. 2 is a side view of a field cultivator according to the present invention. The field cultivator 10 is also provided with an engine 11 arranged at the upper part of the machine body and a clutch (clutch case 11a) not shown in the figure at the lower part of the engine 11. Attached to the power transmission device 12, rotary tillers 15 and 16 rotatably attached to the front of the power transmission device 12, and left and right axles 13a and 14a on the rear of the power transmission device 12 (see FIG. 3). Travel wheels 13 and 14 that are rotatably attached to the vehicle, a handle 18 that extends rearward and obliquely upward from the rear portion of the power transmission device 12, and a coupling mechanism 21 that is attached to the rear end of the power transmission device 12. G shows a running surface.
[0017]
Here, 31 is a traveling auxiliary wheel attached to the front end of the power transmission device 12 so that the position can be adjusted up and down, 32 is a fender that covers the power transmission device 12 and the rotary tillers 15 and 16, and 33 is an upper side of the engine 11. Engine cover 34, air cleaner 35, fuel tank filler cap 36, speed change lever 37, differential lock lever 38, clutch lever 38, and spring 41 for jumping up the working device connected to the coupling mechanism 21 The raising lever 42 is a sinking position adjusting lever that adjusts the sinking position of the working device connected to the connecting mechanism 21.
[0018]
FIG. 3 is a plan view of a cultivator according to the present invention. The cultivator 10 includes a recoil starter knob 51 for starting the engine 11 and a throttle lever 52 for adjusting the output of the engine 11 at the right front portion of the handle 18. The differential lock lever 37 is disposed, the engine switch 53 for stopping the engine 11 is attached to the left rear portion of the handle 18, the clutch lever 38 is attached to the rear portion of the handle 18, and the power transmission device 12 (see FIG. 1) is installed. It shows that the speed change lever 36 is extended from the rear center to the rear, and the flip-up lever 41 is extended from the rear left part of the coupling mechanism 21 to the rear.
[0019]
4 is a cross-sectional view taken along line 4-4 of FIG. 2 and shows the rotary tiller 15 and the power transmission device 12. FIG.
The power transmission device 12 includes a support case 12a and intermediate transmission means 62 (first and second chain gears 63 and 64, first gears 65 and 65, second gear) that are driven via a first chain 61 in the support case 12a. A chain 66).
[0020]
The rotary tiller 15 includes a first tillage shaft 71 that is rotated by the power transmission device 12, and a tillage shaft that is rotated by the power transmission device 12 and that is rotatably fitted between the support case 12 a and the first tillage shaft 71. As a second tillage shaft), a seal cover means 12b having a tillage shaft seal structure provided between the tillage tube 72 and the support case 12a, and a shaft provided between the first tillage shaft 71 and the tillage tube 72. It consists of a seal structure 73, an inner tillage claw 74 attached to the tillage cylinder 72, and an outer tillage claw 75 attached to the first tillage shaft 71.
[0021]
The tilling cylinder 72 is a hollow shaft as a tilling shaft attached to the support case 12a via a bearing 72a. Specifically, the outer cylinder 77 is fixed to the inner cylinder 76 with bolts 78, and the inner tillage claw 74 is rotated through the second gear 81 provided on the inner cylinder 76 in the rotational direction of the traveling wheel 13 (see FIG. 1). Rotate in the same rotation direction b (see FIG. 1) as a (see FIG. 1). Reference numeral 72b denotes a seal member interposed between the tillage cylinder (cultivation shaft) 72 and the support case 12a outside the bearing 72a (in the direction of arrow (1)).
[0022]
The first tillage shaft 71 has a substantially symmetric shape around the central symmetry center line 87 and is also included in the rotary tiller 16.
The rotary tiller 16 is substantially the same as the rotary tiller 15, and the description of the rotary tiller 16 is omitted.
[0023]
The seal cover means 12b having a tillage shaft seal structure is characterized by comprising a rotary cover member 101 attached to the tillage cylinder 72 and a fixed cover member 102 attached to the support case 12a. Next, this will be described in detail.
[0024]
FIG. 5 is a detailed view of part 5 of FIG. 4, showing the rotating cover member 101 and the fixed cover member 102 of the seal cover means 12b.
The rotary cover member 101 includes a disc portion 104 attached to the end of the tillage cylinder 72 by welding, and a female conical portion that extends from the disc portion 104 toward the support case 12a (in the direction of the arrow (2)). 105.
[0025]
The female conical part 105 has an enlarged diameter part 107 and a reduced diameter part 108, the diameter of the enlarged diameter part 107 is set to Da, the diameter of the reduced diameter part 108 is set to Ds, and the central angle of the female cone part 105 is set to θ. It is a thing.
[0026]
The fixed cover member 102 includes an attachment portion 111 attached to the support case 12a, and a male cone portion 112 surrounding the female cone portion 105 of the rotary cover member 101 formed continuously from the attachment portion 111.
[0027]
The interval between the female cone portion 105 and the male cone portion 112 is narrowed in the direction away from the seal member 72b (the direction of arrow (1)). Specifically, the size of the gap between the enlarged diameter portion 107 of the female cone portion 105 and the male cone portion 112 is Sa, and the size of the gap between the reduced diameter portion 108 of the female cone portion 105 and the male cone portion 112 is used. Was Ss (Ss <Sa).
[0028]
FIG. 6 is a front view of the rotating cover member according to the present invention, and shows the female conical portion 105 of the rotating cover member 101.
The female cone portion 105 is also formed by forming a spiral groove 116 on the outer surface 114.
Spiral grooves 116, when turning the tilling tube (cultivating shaft) 72 for tilling, foreign matter such as grass and dirt you reach the female conical portion 105 from the enlarged diameter portion 107 side to the reduced diameter portion 108 side Forward (in the direction of arrow (1)) is a spiral. For example, when the inner cultivating claw 74 on the rotary cultivating device 15 side of the cultivator 10 shown in FIG. 1 is rotated in the rotation direction b, the foreign matter advances in the direction of the left arrow. On the other hand, on the rotary tiller 16 side, the foreign matter advances in the right direction of the arrow.
[0029]
The spiral groove 116 is also a groove in which the peak portion 117 is formed at an acute angle θm. The angle θm was set to 60 °, for example.
The specifications of the spiral groove such as the number of peaks and valley diameter of the spiral groove 116 are arbitrary.
[0030]
Next, the operation of the tillage shaft seal structure of the rotary tiller described above will be described.
When the tilling work is performed with the tiller 10 of FIG. 1, foreign matter such as soil is entangled with the grass as the rotary tillers 15 and 16 are rotated with the rotation of the rotary tillers 15 and 16. A cover member 102 is provided to prevent grass and soil from entering between the support case 12a and the tillage cylinder 72. Specifically, grass or soil entangled with the rotating cover member 101 starts to advance in the axial direction (in the direction of the arrow (2)) on the female cone portion 105 of the rotating cover member 101 and gradually tightens (the diameter decreases). Therefore, when the female cone portion 105 is formed on the rotary cover member 101, the resistance to movement of the grass that is tightened while approaching the seal member 72b by the cone gradually increases, and grass and soil are less likely to enter.
[0031]
Thus, in the seal cover means 12b having the tilling shaft seal structure, the rotary cover member 101 has the female conical portion 105 whose diameter increases toward the support case 12a, and the fixed cover member 102 surrounds the female conical portion 105. Since the male cone portion 112 is provided, the female cone portion 105 that increases in diameter toward the support case 12a serves as a barrier for the progress of the grass that gradually decreases in diameter toward the support case 12a, and the grass and the soil wrapped around the grass enter. It becomes difficult. Therefore, it is possible to suppress the intrusion of grass or soil toward the seal member 72b, and the durability of the seal member 72b can be improved.
[0032]
When grass or soil reaches the female conical portion 105 of the rotary cover member 101 of the seal cover means 12b shown in FIG. 6, the grass and soil are intruded by the rotation (rotational direction b) of the spiral groove 116 of the female conical portion 105. The component force Fg pushed in the reverse direction is received and sent out to the outside as indicated by arrows (5) and (5).
[0033]
Thus, condensation in the sealing cover means 12b of cultivating shaft seal structure, when turned tilling shaft (tillage cylinder 72) for tilling, grass and soil you reach the female conical portion 105 from the expanded side Since the spiral groove 116 proceeding to the radial side is formed on the outer surface 114 of the female conical portion 105, the rotating spiral groove 116 prompts the discharge of grass and soil that has reached the female conical portion 105 as indicated by arrows (5) and (5). be able to. Therefore, the durability of the seal member 72b can be further improved.
[0034]
Since the spiral groove 116 has the peak portion 117 formed at an acute angle (for example, 60 °), the grass that is wound around the female cone portion 105 and tightened by the acute peak portion 117 can be cut. As a result, it is possible to facilitate the discharge of the grass and soil that has reached the female cone portion 105, and to suppress the wrapping of the grass.
[0035]
As shown in FIG. 5, in the seal cover means 12b having the tilling shaft seal structure, the interval between the female cone portion 105 and the male cone portion 112 is narrowed in the direction away from the seal member 72b. The grass returned in the direction away from the seal member 72b (in the direction of the arrow (1)) by (see FIG. 6) is compressed at the narrow diameter portion 108 and further cut. As a result, the wrapping of the grass can be further suppressed, and the invasion of the grass can be suppressed.
[0036]
Next, another embodiment of the tillage shaft seal structure according to the present invention will be described.
FIG. 7 is a diagram showing another embodiment of FIG. 6. The same components as those in the embodiment shown in FIGS.
In the female cone portion 105B, an edge portion 122 formed by the outer surface 114 and the end surface 121 is formed at an acute angle θe. The angle θe is 60 °, for example.
[0037]
By forming the edge portion 122 at an acute angle, the entire circumference of the edge portion 122 is a cutting edge. If the sharp edge 122 is formed on the entire circumference, the grass can be cut more reliably. That is, the grass that could not be cut at the mountaintop portion 117 can be cut at the final end surface 121, and the winding of the grass can be further suppressed and the invasion of the grass can be suppressed.
[0038]
A spiral groove similar to the spiral groove shown in the embodiment of the present invention can be formed on the outer surface of the disc portion 104 of the rotary cover member 101. Specifically, a spiral groove that guides foreign matter to the center side of the disc portion 104 is formed by the rotation of the rotary cover member 101 of FIG. As a result, it is possible to prevent the foreign matter from adhering to the outer surface of the disc portion 104 of the rotary cover member 101 from traveling.
The fixed cover member is configured to be attached to the support case, but a substantially similar male conical portion 112 can be formed integrally with the support case.
[0039]
【The invention's effect】
The present invention exhibits the following effects by the above configuration.
In claim 1, the seal cover means includes a rotating cover member attached to the tilling shaft and a fixed cover member attached to the support case, and the rotating cover member has a female conical portion whose diameter increases toward the support case. Since the fixed cover member has a male conical portion surrounding the female conical portion, the female conical portion whose diameter increases toward the support case serves as a barrier for the progress of the grass that gradually decreases in diameter toward the support case. The soil wrapped with the grass becomes difficult to invade. Therefore, it is possible to suppress the intrusion of grass or soil toward the seal member, and the durability of the seal member can be improved.
[0040]
According to claim 2, when turning the tiller axis for tilling, so to form a helical groove foreign matter reaches the female cone progresses from enlarged side to diametrically contracted on the outer surface of the female cone, rotates The spiral groove can facilitate the discharge of grass and soil that has reached the outer surface of the female cone. Therefore, the durability of the seal member can be further improved.
[0041]
According to the third aspect of the present invention, since the spiral groove is formed with a sharp peak, the grass that is wound around the female cone and tightened can be cut by the sharp peak. As a result, it is possible to smoothly discharge the grass and soil that have reached the female cone, and to suppress the wrapping of the grass.
[0042]
According to the fourth aspect of the present invention, since the distance between the female cone portion and the male cone portion is narrowed in the direction away from the seal member, the grass returned in the direction away from the seal member by the spiral groove is narrow. It is further cut by the compression action. As a result, the wrapping of the grass can be further suppressed, and the invasion of the grass can be suppressed.
[0043]
According to the fifth aspect of the present invention, since the female cone portion has a shape in which an edge portion formed by the outer surface and the end surface is formed at an acute angle, the edge portion becomes a cutting edge. A sharp edge can cut the grass more reliably. In other words, the grass that could not be cut at the top of the mountain can be cut at the end face, so that the wrapping of the grass can be further suppressed and the invasion of the grass can be suppressed.
[Brief description of the drawings]
FIG. 1 is a perspective view of a walking rotary tiller that employs a tiller shaft seal structure according to the present invention. FIG. 2 is a side view of the tiller according to the present invention. FIG. 3 is a plan view of the tiller according to the present invention. 4 is a sectional view taken along line 4-4 in FIG. 2. FIG. 5 is a detailed view of part 5 in FIG. 4. FIG. 6 is a front view of a rotating cover member according to the present invention. FIG. 8 is an explanatory diagram of a structure of a tiller claw shaft support portion of a conventional rotary tiller [description of symbols]
DESCRIPTION OF SYMBOLS 10 ... Walking type rotary tiller, 12a ... Support case, 12b ... Seal cover means, 15 ... Left rotary tiller, 16 ... Right rotary tiller, 72 ... Tillage shaft (plowing cylinder), 72a ... Bearing, 72b ... Seal member 101 ... Rotary cover member 102 ... Fixed cover member 105 ... Female conical portion 112 ... Male conical portion 114 ... External surface of female conical portion 116 ... Helix groove 117 ... Mountain top portion 121 ... Female conical portion 122: edge portion, Da: diameter of the enlarged diameter portion, Ds: diameter of the reduced diameter portion, θe: angle of the edge portion, θm: angle of the peak portion.

Claims (5)

A tiller shaft is rotatably supported by the support case via the bearing, and a seal member that prevents foreign matter directed to the bearing is interposed between the tillage shaft and the support case outside the bearing, and the foreign matter directed to the seal member. A rotary shaft tiller shaft sealing structure of a rotary tiller in which a seal cover means for reducing the outer surface of the seal member is interposed between the tiller shaft and the support case,
The seal cover means comprises a rotating cover member attached to the tilling shaft and a fixed cover member attached to the support case,
The rotary cover member has a female conical portion that expands toward the support case, and the fixed cover member has a male conical portion that surrounds the female conical portion. Construction. Claims wherein the tilling shaft when turned for tilling, characterized in that the foreign matter reaches the female cone portion is formed a spiral groove going from diameter side to the reduced diameter side to the outer surface of the female cone The tilling shaft seal structure of the rotary tilling device according to Item 1.   The tiller shaft seal structure of the rotary tiller according to claim 2, wherein the spiral groove has a mountain top portion formed at an acute angle.   The tilling shaft seal structure of the rotary tilling device according to claim 2, wherein a space between the female cone portion and the male cone portion is narrowed in a direction away from the seal member.   5. The tiller shaft seal structure for a rotary tiller according to claim 2, wherein the female cone part has an edge formed by an outer surface and an end surface at an acute angle.

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