JP6667324B2 - Mission case - Google Patents

Description

  The present invention relates to a transmission case for a cultivator that covers and protects a two-way transmission that transmits the power of an engine to a drive unit of a traveling wheel and a drive unit of a rotary.

The cultivator that runs with the power of the engine and cultivates with a rotary equipped with a tilling claw transmits the working system mission for transmitting to the rotary and the traveling system mission for transmitting to the traveling wheels at the optimum rotational speed. Connected to one engine via a speed reducer or the like.
The work-related mission and the traveling-related mission are stored and protected in a transmission case so that the transmission function is not deteriorated or the components are damaged due to the invasion of foreign matter such as soil and grass between the combined components. I have.

In such a cultivator, in response to a user's request, the maker may perform a task of replacing a rotary mounted for performing different tilling operations on the same cultivator body with another rotary. .
At that time, in a conventional transmission case in which a traveling transmission mission and a work transmission mission are integrally stored as in Patent Document 1 below, the entire transmission case must be disassembled at one time, and the replacement work for the manufacturer is not required. It is difficult and causes a large cost burden including parts.
Further, in repairing or replacing parts due to breakage or wear of the gears or chains of the rotary, the transmission case must be once removed and then reattached after completion, and the work of attaching and detaching the transmission case is very troublesome.

The present inventors have been conducting research to make it possible to efficiently perform low-cost rotary replacement work and maintenance, which has been difficult in this way, and have to replace the mission part for rotating the traveling wheels. Since it is not necessary, it was thought that if only a part of the mission case storing the mission part for rotating the rotary was separated, the rotary replacement work would be easily performed.
However, when the transmission case is actually divided into two, the connection strength and the connection position of the divided cases on both sides need to be accurate due to the transmission structure for transmitting the rotation and the rotary support structure. Practical application was very difficult.

Japanese Patent Application No. 2014-23450

  The present invention has been made in view of the above circumstances, and a mission for rotating a traveling wheel and a mission for rotating a rotary are combined at an accurate position and are integrally protected, so that when performing maintenance on a rotary, It is an object of the present invention to provide a transmission case that can be easily attached and detached, and when a rotary is replaced, a mounted rotary can be easily replaced with another rotary.

  In order to achieve the above object, the present invention provides a non-replaceable metal fixed case portion which divides a transmission case into two, stores a traveling system transmission for transmitting rotation from a driving shaft of an engine to a driving shaft of traveling wheels, and An exchangeable metal detachable case housing a working system transmission for transmitting rotation from the drive shaft to the rotary drive shaft, wherein the fixed case and the detachable case penetrate through the two divided openings. A pin mechanism that enables positioning by driving a metal positioning pin into the provided positioning pin hole and discharge of the driven positioning pin into a pin punching space; A flange contact surface having a bolt hole into which a plurality of fixing bolts can be screwed is formed on the periphery of the opening protruding from the In the divided opening of the detachable case portion, a flange having a plurality of bolt holes is formed around the periphery so that the fixing bolt can be inserted into a bolt hole of the flange contact surface while being able to closely contact the flange contact surface. The pin mechanism is configured such that the pin punching space is formed at a depth at which the positioning pin can be pulled out from the positioning pin hole outside an opening peripheral edge on a rear side of a flange contact surface of the fixed case portion. With the positioning pin hole, with the hole end facing the pin punching space, the detachable case portion can be positioned with respect to the fixed case portion on the flange contact surface of the fixed case portion and the flange of the detachable case portion. The positioning pin has a diameter that allows the positioning pin to be pressed into the positioning pin hole in a press-fit state.

  According to a second aspect of the present invention, in the above invention, the material of the fixed case portion is made of a metal material softer than the material of the positioning pin, and the positioning pin has the same diameter as or slightly larger than the diameter of the positioning pin hole. It is characterized by the following.

  According to a third aspect of the present invention, in the above-mentioned invention, the positioning pin hole is formed in the flange and the flange contact surface of the opposite portions with respect to the center of the opening of the fixed case portion and the removable case portion, respectively. It is characterized in that a pair is provided.

  According to a fourth aspect of the present invention, in the above invention, a metal bracket fixed by bolts to the fixed case portion and the detachable case portion is installed, and a flange of the detachable case portion is fixed to an intermediate portion of the bracket. A bent portion is formed so as to be pressed against the portion.

  According to a fifth aspect of the present invention, in the above invention, a metal bracket fixed by bolts to the fixed case portion and the detachable case portion is provided, and a split opening on the fixed case portion side is provided at an intermediate portion of the bracket. A bent portion having a shape capable of contacting the positioning pin is formed at a position where the positioning pin does not come off from the positioning pin hole of the portion.

Rotary replacement of the conventional cultivator had to replace the entire transmission case together, which was not easy, but the present invention provides a transmission system in which the transmission case transmits rotation to the drive shaft of the traveling wheels. Is divided into two parts: a fixed case portion for storing the rotation, and a detachable case portion for storing a work system mission for transmitting rotation to the drive shaft of the rotary. By attaching and detaching only the detachable case portion while the fixed case portion is fixed, The work of replacing the mounted rotary with another rotary can be easily performed.
At that time, by inserting the positioning pins into the positioning pin holes in a press-fit state, it becomes possible to fix the detachable case part to the fixed case part at a highly accurate and precise position. By inserting and tightening the fixing bolt into the bolt hole on the flange contact surface, the divided opening can be firmly connected.
Next, by detaching the positioning pin and the fixing bolt, the detachable case part can be easily separated from the fixed case part. At this time, the positioning pin is taken out by using a pin punching tool on the flange side. By simply hitting out the positioning pin with a hammer or the like from the positioning pin, the positioning pin can be easily discharged from the positioning pin hole into the pin punching space, and the positioning pin which is conventionally difficult to pull out can be easily extracted by the present invention. .
Further, if the fixing bolt is further removed from the flange with a tool such as a spanner, the detachable case portion can be easily separated from the fixed case portion in a short time, so that the efficiency of the rotary removing operation can be greatly improved and the cost can be reduced.

In the invention according to claim 2, the positioning pin can be press-fitted into the positioning pin hole by driving a positioning pin having a diameter slightly larger than the diameter of the positioning pin hole into the positioning pin hole. At this time, when the positioning pins enter the positioning pin holes, the metal positioning pin holes that are softer than the positioning pins are pressed from the inside and are inserted while undergoing expansion deformation. As a result, the positioning pin holes are strongly tightened. As a result, the positioning pin can be firmly fixed at an accurate position.
Also, at this time, by stopping the front end of the positioning pin just before the end of the positioning pin hole, a stopper function occurs in a portion where the positioning pin does not pass through the positioning pin hole, and the positioning pin which has received a force such as vibration is generated. Projection from the positioning pin hole to the pin punching space is prevented, and it is possible to prevent the positioning pin from coming off the positioning pin hole on the flange side.
If the positioning pin hole and the positioning pin have the same diameter, the positioning pin hole and the positioning pin are fixed in close contact with no gap if the component precision is high, but depending on the level of component precision. In some cases, there is a portion where pressure deformation occurs and a portion where pressure deformation does not occur. Also in this case, the positioning pin hole strongly tightens the positioning pin, and the positioning pin can be firmly fixed at an accurate position.

  In the invention described in claim 3, the pair of the positioning pin holes provided in the flange and the flange contact surface are opposite sides with respect to the center of the opening of the fixed case portion and the detachable case portion. By separating the parts, the two parts are separated from each other, and the flange and the flange contact surface can be temporarily fixed to the fixed case part by driving only the positioning pin into the flange before fixing with the fixing bolt. In addition, as compared with the case where the positioning pin holes are provided close to each other by the distance, the mounting error can be reduced, and more accurate positioning can be performed.

In the invention described in claim 4, the detachable case portion is more firmly fixed to the fixed case portion by a bracket bridged between the fixed case portion and the detachable case portion.
At this time, the bent part presses the flange of the work case part at the middle part of the bracket toward the fixed case part, so that even if the bolt fixed to the detachable case part is loosened, the bent part works and it is attached to and detached from the fixed case part It is possible to continuously press the case portion and maintain the strong fixing of the detachable case portion.

In the invention according to claim 5, the positioning is performed when a force is applied in a direction in which the positioning pin, which is driven by the impact or vibration of the cultivator, comes out of the positioning pin hole of the divisional opening on the fixed case part side. As the head of the pin protrudes from the positioning pin hole, the bent portion of the bracket intermediate portion abuts on the head of the positioning pin and stops. Since the position of the stopped positioning pin is not separated from the positioning pin hole of the divided opening on the fixed case portion side, the positioning pin has been fitted into both the positioning pin holes of the detachable case portion and the fixed case portion. The state is maintained.
As a result, even if the fixing bolt fixing the detachable case portion to the fixed case portion is loosened, the detachable case portion can be accurately fixed at a predetermined position with respect to the fixed case portion.

(A) of this invention is each side view of the tilling machine which shows the aspect which attached the rotary, and (B) shows the aspect which attached another rotary. It is a side view of this invention. FIG. 3 is a side view showing a state in which the detachable case part of FIG. 2 is separated from a fixed case part. (A) is a cross-sectional view of the main part of the divided opening viewed from the front, and (B) is an enlarged cross-sectional view thereof. It is an expanded sectional view showing the important section of the pin mechanism in the state where a positioning pin was punched out. 2A is a sectional view taken along line AA of FIG. 2, and FIG. 2B is a sectional view taken along line BB of FIG.

An embodiment for carrying out the mission case of the present invention will be described below with reference to the drawings.
As shown in FIGS. 1A and 1B, the present invention covers a transmission case for a cultivator that covers and protects a mission for driving a traveling wheel H and various types of rotaries R1, R2 with the power of an engine E. In the transmission case, as shown in FIG. 2, a traveling system for transmitting rotation of the driving shaft 2 to a driving shaft 3 of the traveling wheel with respect to a driving shaft 2 of an engine connected to the engine. Two types of missions are stored: a mission 5 and a work mission 6 transmitted to the rotary drive shaft 4.

  As shown in FIG. 1, the present invention divides the transmission case into two parts, a fixed case part 7 storing the traveling system transmission and a detachable case part 8 storing the working system transmission. By making the split openings 9 and 11 detachable, it is possible to replace the rotary R1 connected to the work system mission 6 separated from the traveling system mission 6 with another rotary R2 for the same cultivator body. I do.

  FIG. 2 is an enlarged view of a transmission case portion of the cultivator of FIG. 1, and includes a fixed case portion 7 for storing the traveling system mission 5 and a detachable case portion 8 for storing the working system mission 6. FIG. 3 shows a state in which the fixed case section 7 and the detachable case section 8 are separated from each other, and FIG. (B) shows the detachable case portion 8 separated from the fixed case portion 7.

FIG. 1 shows a cultivator in which a transmission portion for transmitting rotation from the engine E to a drive shaft of the engine is separately covered and protected by a transmission cover K.
Although not shown, the traveling transmission 5 and the work transmission 6 can use various rotation transmitting components such as gears, sprockets, chains, pulleys, and V-belts.

As described above, according to the present invention, the transmission case is divided into a fixed case 7 and a detachable case 7, and the fixed case 7 itself is, for example, shown in FIGS. A mode in which both sides of the traveling system transmission 5 from the drive shaft 2 of the engine to the drive shaft 3 of the traveling wheel H are surrounded, and the periphery of the flange portion provided at the joint on both sides is fastened using a plurality of fixing bolts 29. It is possible.
Then, as shown in FIGS. 4A and 4B and FIG. 6A, the rotary shaft is moved from the drive shaft 2 of the engine common to the traveling system A split opening 9 having a flange contact surface 10 at a portion protruding from a peripheral edge of the opening is formed so that a working system mission 6 for rotating the driving shaft 4 toward the direction of the driving shaft 4 can pass therethrough. Form.

As for the detachable case portion 8 itself, for example, as shown in FIGS. 2 and 4 (a), the working system mission 6 is surrounded from both sides by two cases, and the mating openings on both sides are welded. It is possible to adopt a fixed mode. In this embodiment, the detachable case portion 8 is integrated with the work mission 6 so as not to be detached from the work mission 6.
Instead of fixing the joints of the cases on both sides by welding as described above, it is also possible to adopt a mode in which the opposed flange portions are fastened with fixing bolts. In this embodiment, the attachment / detachment case portion 8 can be attached to / detached from the work system mission 6 by attaching / detaching the fixing bolt.
As shown in FIG. 6B, the detachable case portion 8 is provided with an opening through which rotation can be transmitted from the drive shaft 2 of the engine to the work system mission 6, and the opening of the opening is formed. On the periphery, a divided opening 11 having a flange 17 having a contact surface 18 which is closely opposed to the flange 10 of the divided opening 9 of the fixed case portion 7 is formed.

The fixed case 7 has an engine drive shaft opening 24 and a traveling wheel drive shaft opening 25, and the detachable case 8 has a rotary drive shaft opening 26, which is provided outside the transmission case. Power can be transmitted to the traveling wheel H and the rotary.
Further, since the drive shaft 3 of the traveling wheel H and the rotary drive shaft 4 have different rotation speeds, as shown in FIG. Speed reducers 27 and 28 for adjusting the rotation speed and transmitting the rotation are provided.

  Further, as shown in FIGS. 4A and 4B, the detachable case portion 8 can be positioned with high precision by the positioning pins 15 in the two divided openings 9 and 11 with respect to the fixed case portion 7. And a pin mechanism 32 having two functions that allows the positioning pin 15 to be easily extracted.

Next, a structure for obtaining a highly accurate positioning function among the two functions of the pin mechanism 32 will be described first.
As shown in FIGS. 2 and 4, (a) and (b), the pin mechanism 32 is provided between the flange contact surface 10 of the fixed case portion 7 and the contact surface 18 of the flange 17 of the detachable case portion 8. The positioning pin 15 is driven into the flange contact surface 10 of the fixed case portion 7 and the flange 17 of the detachable case portion 8 at a position where the detachable case portion 8 can closely contact the fixed case portion 7 with high accuracy. A plurality of positioning pin holes 13 and 14 are provided.
The precise position that can be closely contacted with the high precision is such that the components configured by the work system mission 6 in the detachable case portion 8 with respect to the drive shaft 2 of the engine can determine the exact positional relationship as designed. In addition, it is a position where the contact surface 18 of the flange 17 of the detachable case portion 8 can be fixed in close contact with the flange contact surface 10 of the fixed case portion 7.

The positioning pin holes 13 and 14 are used to fix the positions of the flange contact surface 10 and the flange 17, for example, as shown in FIGS. A configuration is possible in which a pair of flanges 17 and flange contact surfaces 10 are provided on opposite sides with respect to the center of the eight divided openings 9 and 11, respectively.
In this embodiment, the pair of the positioning pin holes 13 and 14 provided in the flange 17 and the flange contact surface 10 is located at a more distant position. Before fixing, the detachable case portion 8 can be stably temporarily fixed to the fixed case portion 7 by driving only the positioning pins 15 into the flange 17 and the flange contact surface 10. In this state, the detachable case portion 8 is fixed to the fixed case portion 7 at an accurate position by the fixing bolts 12.

Next, a structure that allows the positioning pin 15 of the pin mechanism 32 to be easily extracted will be described.
As shown in FIGS. 4A and 4B, the pin mechanism 32 has a pin punching space communicating with the positioning pin hole 13 in the divided opening 9 behind the flange contact surface 10 of the fixed case portion 7. 16 are provided.
The pin punching space 16 is a space having a depth and a width exceeding the length of the positioning pin 15 in the center direction of the positioning pin hole 13.
By providing the pin punching space 16, the positioning pin 15 is beaten out with a hammer or the like using a pin punching tool, and as shown in FIG. The pin 15 can be easily discharged.
The depth of the pin punching space 16 is, for example, when the length of the positioning pin 15 is about 15 mm, and the depth of the positioning pin 15 is about 3 mm larger than the length of the positioning pin 15 by 18 mm. It becomes possible to punch out and extract into the pin punching space 16.

After driving the positioning pins 15 into the positioning pin holes 13 and 14 of the pin mechanism 32 having the two functions as described above, as shown in FIG. Fix it.
For this reason, as shown in FIG. 6, a plurality of bolt holes 19 and 20 through which the fixing bolts 12 can be screwed are provided at the flange contact surface 10 and the flange 17 at intervals necessary for obtaining the strength of the connection.
The split openings 9 and 11 on both sides may be connected in an airtight manner with a packing made of paper or the like interposed between the contact surface 18 of the flange 17 and the contact surface 18 of the flange 17.

According to the present invention, with the above structure, the fixed case portion 7 and the detachable case portion 8 are accurately positioned by the positioning pins 15 driven into the positioning pin holes 13 and 14, and the positioning pins 15 are driven accurately. At this position, the fixing bolt 12 is screwed into each of the bolt holes 19 and 20 firmly, and as shown in FIG. 2, the fixed case portion 7 and the detachable case portion 8 are strongly coupled at the correct position.
Then, when replacing the rotary, as shown in FIG. 5, the positioning pin 15 is knocked out of the pin punching space 16, and the fixing bolt 12 is removed as shown in FIG. The contact surface 18 of the flange 17 of the detachable case portion 8 is easily separated from the flange contact surface 10 of the portion 7.
When another rotary is mounted, the divisional opening 11 of the detachable case portion 8 storing the work system mission 6 of the rotary is aligned with the divisional opening 9 of the fixed case portion 7, and the positioning pin hole 13 is inserted. The positioning pin 15 is driven into the hole 14 to position the bolt, and the fixing bolt 12 is screwed into each of the bolt holes 19 and 20 to be tightened, thereby connecting the detachable case section 8 to the fixed case section 7 and completing the mounting of the rotary. .
That is, the fixing case 7 and the detachable case 8 can be easily attached and detached by the positioning pins 15 and the fixing bolts 12.

Further, the material of the fixed case portion 7 may be a metal material softer than the material of the positioning pins 15, and the positioning pins 15 may have the same diameter as or slightly larger than the diameters of the positioning pin holes 13 and 14. .
For example, when the positioning pin 15 is made of steel, the fixed case part 7 is made of aluminum, and the diameter of the positioning pin holes 13 and 14 is 6.00 mm, the diameter of the positioning pin 15 used for this is 6 mm. The diameter of the positioning pin holes 13 and 14 may be the same as or slightly larger than that of the positioning pin holes 13 and 14.

In this embodiment, when the positioning pin hole 13 of the fixed case portion 7 has a slightly smaller diameter than the positioning pin 15, the positioning pin 15 enters the positioning pin holes 13 and 14, so that the metal is softer than the positioning pin 15. The positioning pin hole 13 is pressed from the inside and deformed, and the positioning pin 15 is press-fitted. As a result, the positioning pin hole 13 strongly tightens the positioning pin 15 so that the positioning pin 15 can be firmly fixed at the correct position. .
Also, at this time, the tip of the positioning pin 15 is stopped slightly short of the end of the positioning pin hole 13 to stop the expansion of the aluminum hole diameter beyond that, thereby positioning the positioning pin 15 in the positioning pin hole 13. A stopper function is generated at a portion where the pin 15 has not passed, and the positioning pin 15 is prevented from moving in the direction of the pin punching space 15 due to external pressure such as strong vibration or impact, and is prevented from falling off the flange 11a. .

  When the positioning pin hole 13 and the positioning pin 15 have the same diameter, the positioning pin hole 13 and the positioning pin 15 are fixed in a tight state without any gap if the precision of the parts is high. Depending on the level, there may be a part where the pressing deformation occurs and a part where the pressing deformation does not occur, but even in this case, the positioning pin hole 13 strongly tightens the positioning pin 15 so that the positioning pin 15 can be accurately and firmly fixed at the correct position. Becomes

Further, in this embodiment, when the positioning pin 15 is removed to replace the rotary, if the positioning pin 15 is hit with a hammer or the like from the side of the detachable case portion 8 through a pin removing tool, the positioning of the soft aluminum is performed. The pin hole 13 is advanced in the positioning pin hole 13 while the tip end of the positioning pin 15 is expanded, and finally can be discharged into the pin punching space 15 as shown in FIG.
Usually, if the positioning pin 15 is driven into the head, it is extremely difficult to pull out from the working case portion 8 side. However, in the present invention, the positioning pin 15 is extremely easily driven out into the pin punching space 16 as described above. The positioning pin 15 can be removed.

As shown in FIG. 2, a bracket 21 made of a metal plate such as iron is disposed so as to cover a connection portion between the fixed case portion 7 and the detachable case portion 8, and bolts 22 and 23 are provided on both sides of the bracket 21. Thus, the fixing case 7 and the detachable case 8 can be cross-linked and fixed.
At this time, as shown in FIG. 3 (c) and FIG. 4 (b), a part around the flange 11a of the working case portion 8 is pressed toward the fixed case portion 7 at an intermediate portion of the bracket 21. By providing the bent portion 21a which can be brought into contact, the connection between the fixed case portion 7 and the detachable case portion 8 can be further strengthened.
In this embodiment, the bent portion 21a presses the flange 11a of the work case portion 8 toward the fixed case portion 8 at the intermediate portion of the bracket 21, and even if the bolt 23 fixed to the detachable case portion 8 is loosened, the bent portion 21a is The detachable case portion 8 is pressed by the fixed case portion 7 and the fixation by the bracket 21 is maintained.
Reference numerals 22a, 22b, 23a, and 23b in FIGS. 3 and 4 denote bolt holes into which bolts 22 and 23 are inserted to fix both sides of the bracket 21 to the fixed case portion 7 and the detachable case portion 8, respectively. A nut 23c is screwed onto the bolts 22, 23.

  Further, both sides of a bracket 21 made of a metal plate made of iron or the like disposed to cover the connection portion between the fixed case portion 7 and the detachable case portion 8 are bridged to the fixed case portion 7 and the detachable case portion 8 with bolts 22 and 23. The positioning pin 15 can be brought into contact with the positioning pin 15 at a position where the driven positioning pin 15 does not come off from the positioning pin hole 13 of the divisional opening 9 on the side of the fixed case 7 at the intermediate portion of the bracket 21. A form in which a bent portion 21a having a shape is formed is possible.

In this embodiment, the position at which the tip of the positioning pin 15 does not separate from the positioning pin hole 13 of the divisional opening 9 on the fixed case portion 7 side is defined by the opening end of the positioning pin hole 13 on the fixed case portion 7 side. The shortest distance to the bent portion 21 a of the bracket 21 is a position shorter than the length of the positioning pin hole 13. That is, the interval from the positioning pin hole 14 on the side of the detachable case portion 8 to the bent portion 21a of the bracket 21 is smaller than the interval obtained by subtracting the length of the positioning pin hole 14 from the length of the positioning pin 15. is there.
In this embodiment, for example, FIG. 4B shows a state in which the bent portion 21a of the bracket 21 is slightly away from the head of the positioning pin 15, but the positioning pin 15 receives the seismic intensity and impact of the tilling machine. When the bracket 21 is moved in the escape direction, the bent portion 21a of the bracket 21 hits the head of the positioning pin 15, so that the bent portion 21a can be prevented from falling out of the positioning pin hole 13 of the divisional opening 9 on the fixed case portion 7 side.

  If the head of the positioning pin 15 does not hit the bent portion 21a of the bracket 21, the tip of the positioning pin 15 will fall out of the positioning pin hole 13 on the fixed case 7 side, and if it comes off, Even if the positioning pin 15 is fixed in the positioning pin hole 14 of the split opening 11 on the detachable case portion 8 side, the split opening 9 on the fixed case portion 7 side and the split opening 9 on the detachable case portion 8 side The function of fixing the unit 11 at the correct position is lost.

  Therefore, in the present invention, in order to maintain the positioning function of the positioning pin 15 effectively, it is preferable that the state where the positioning pin 15 is inserted deeply into the positioning pin hole 13 on the fixed case portion 7 side is maintained. It is preferable that the distance from the positioning pin hole 14 on the side of the portion 8 to the bent portion 21a of the bracket 21 is set to be small.

In addition, the rotary and the rotary cover mounted on the cultivator are supported by the rotary support frame 31 in front of the fuselage, and in connection with the rotary to be replaced, it is necessary to exchange various attachments such as a tilling depth adjustment wheel. In some cases.
These parts may be separately attached to the fixed case part 7 with bolts or the like, or may be fixed to the detachable case part 8, and can be attached to each part according to the structure of the parts.
For example, as shown in FIG. 2, when the bracket 21 is attached to and detached from the fixed case portion 7 and the detachable case portion 8, the rotary support frame 31 is attached to the detachable case portion 8 at the same time as the attachment and detachment. A mode of attaching and detaching at 22, 23 is possible.
In this aspect, the replacement of the rotary support frame 31 can be performed simultaneously with the replacement of the rotary, so that the replacement operation can be performed easily and in a short time.
When the rotary support frame 31 is fixed to the fixed case portion 7 and the detachable case portion 8, a metal such as aluminum, which is a material of the fixed case portion 7 and the detachable case portion 8, supports a rotary with a large load. Because it is necessary, it is better to use a thick one with high strength.

  Although the mission case of the present invention is used for a cultivator whose rotary is replaceable, it can be used even for a cultivator that does not replace the rotary in order to facilitate maintenance of the rotary portion.

DESCRIPTION OF SYMBOLS 1 Mission case 2 Engine drive shaft 3 Traveling wheel drive shaft 4 Rotary drive shaft 5 Travel system mission 6 Work system mission 7 Fixed case section 8 Removable case section 9 Split opening 10 Flange contact surface 11 Split opening 12 Fixed Bolt 13 Positioning pin hole 14 Positioning pin hole 15 Positioning pin 16 Pin punching space 17 Flange 18 Contact surface 19 Bolt hole 20 Bolt hole 21 Bracket 21a Bent portion 22 Bolt 22a Bolt hole 22b Bolt hole 22c Nut 23 Bolt 23a Bolt hole 23b Bolt Hole 23c Nut 24 Engine drive shaft opening 25 Running wheel drive shaft opening 26 Rotary drive shaft opening 27 Reduction unit 28 Reduction unit 29 Fixing bolt 30 Welding unit 31 Rotary support frame 32 Pin mechanism E Engine H Running wheel K Mission cover R1 Rotary R2 Rotary

Claims (5)

A non-exchangeable metal fixed case portion storing a traveling system transmission for transmitting rotation from the drive shaft of the engine to the drive shaft of the traveling wheel by dividing the transmission case into two parts, and rotating the drive shaft of the engine to the drive shaft of the rotary. Consisting of an exchangeable metal detachable case that stores the work mission to be transmitted,
In the fixed case portion and the detachable case portion, positioning is performed by driving a metal positioning pin into a positioning pin hole penetrating through the two divided openings, and discharging of the driven positioning pin into a pin punching space. Equipped with a pin mechanism that enables removal and
The split opening of one of the fixed case portions has a flange contact surface having a bolt hole through which a plurality of fixing bolts can be screwed, and the split opening of the other detachable case portion is formed at the periphery of the projected opening. The part is formed with a flange provided with a plurality of bolt holes that allow the fixing bolt to be inserted into a bolt hole of the flange contact surface while allowing the flange to contact the flange contact surface on the periphery,
The pin mechanism is configured such that the pin punching space is formed at a depth at which the positioning pin can be pulled out from the positioning pin hole outside a peripheral edge of an opening on a rear side of a flange contact surface of the fixed case portion. The hole is made so that the hole end faces the pin punching space, and the detachable case portion is penetrated through the flange contact surface of the fixed case portion and the flange of the detachable case portion so that the detachable case portion can be positioned with respect to the fixed case portion. A transmission case, wherein the diameter of the positioning pin is set to a size capable of being pressed into the positioning pin hole in a press-fit state.   2. The transmission case according to claim 1, wherein a material of the fixed case portion is made of a metal material softer than a material of the positioning pin, and the positioning pin has the same diameter as or slightly larger than the diameter of the positioning pin hole.   The pair of positioning pin holes are provided in the flange and the flange abutting surface at portions opposite to each other with respect to the center of the opening of the fixed case portion and the detachable case portion, respectively. The stated mission case.   A metal bracket fixed by bolts to the fixed case portion and the detachable case portion was erected, and a bent portion was formed at an intermediate portion of the bracket so that the flange of the detachable case portion abuts against the fixed case portion so as to be pressed. The mission case according to any one of claims 1 to 3, wherein: A metal bracket fixed with bolts to the fixed case portion and the detachable case portion is erected, and a positioning pin is provided at an intermediate portion of the bracket at a position where the positioning pin does not detach from the positioning pin hole of the split opening on the fixed case portion side. The transmission case according to any one of claims 1 to 4, wherein a bent portion having a shape capable of contacting the positioning pin is formed.

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