JP7382657B2 - Gear material holding device and gear material attachment method - Google Patents

Description

The present invention relates to a holding device for attaching gear material to a machine tool when manufacturing gears.

In order to manufacture gears, various processes are performed on a disc-shaped member with a hole in the center. For example, pre-processing includes cutting the outer surface of a rough disk-shaped member to give it a precise shape, forming a conical outer shape for a bevel gear, and a process called gear cutting. . In all of these processes, gear material is attached to the rotating part of a machine tool such as a lathe, and the necessary processing is performed while rotating the gear.

In order to attach gear material to a machine tool, a chuck that grips the gear material from the outside with a plurality of claws is usually used, as disclosed in Patent Document 1. Moreover, Patent Document 2 and Patent Document 3 describe that a gear material is attached to a machine tool by sandwiching the material between members that are in contact with the upper and lower surfaces of the gear material.

Public utility model publication No. 5-16017 Japanese Patent Application Publication No. 2005-262354 JP 2004-42183 Publication Patent Publication

If the outer surface of the gear material is gripped with a chuck as in the past, it is impossible to apply a tool or the like to the area in contact with the chuck or its vicinity, making it impossible to process the material. Therefore, when machining the entire circumference of the outer surface, it is necessary to shift the position of the claws and re-chuck, and sequentially process the parts that are not hidden by the chuck. Further, in the case of a tooth trace inclined with respect to the axial direction, such as a helical gear or a screw gear, if one tooth trace cannot fit between the chucks, the tooth trace cannot be formed in the first place.

In the inventions of Patent Document 2 and Patent Document 3, the gear material is sandwiched between members that are in contact with the upper and lower surfaces, so the side surfaces of the gear material are open. However, these have very complicated structures and are expensive. If there are many types of gears to be manufactured, various types of equipment will be required, which will increase costs. Moreover, in order to attach and detach the gear material, it is also necessary to attach and detach a member that contacts the upper surface of the gear material, which takes time. In the case of a gear having a truncated conical shape, such as a spiral bevel gear, it is difficult to sandwich the gear from above and below, and even if it can be sandwiched, it is difficult to process the truncated conical portion.

Furthermore, in the inventions of Patent Documents 1 to 3, it is difficult to accurately align the center axis of the gear material. Particularly in the initial process, the center position of the hole in the center of the gear material and the position of the outer periphery may not exactly match. In this case, if the outer surface is gripped and processed while being rotated as in Patent Document 1, the axial center of the finished product will remain offset from the center position of the outer periphery.

The present invention provides a gear material holding device and a gear material mounting method that can be mounted while accurately aligning the rotating shaft of a machine tool with the center position of a hole in the center of the gear material, and that can be easily attached and detached. The purpose is to

In order to solve the above problems, the gear material holding device of the present invention is a device for rotatably holding gear material having a circular hole in the center in a machine tool, and the gear material holding device has a circular hole in the gear material. a holding member having a hollow cylindrical portion in contact with the side wall of the holding member; a pull rod inserted into the hollow cylindrical portion of the holding member; A divided section is formed by multiple cuts,
A tapered part is formed at the end of the pull rod so that the outer diameter increases toward the tip, and the holding member can be detachably attached to the machine tool. It is designed to be able to move back and forth along the length of the member, and when the tapered part of the pull rod enters the divided part of the holding member, the divided part of the holding member expands and the circular hole in the gear material is expanded. It is designed to be pressed against the side wall of the Alternatively, it is a device for holding a gear material having a circular hole in the center, and includes a machine tool connecting member connected to a machine tool and a hollow cylindrical part that contacts the side wall of the circular hole of the gear material. a member and a pull rod inserted into a hollow cylindrical portion of the holding member, and an end portion of the hollow cylindrical portion of the holding member is formed with a divided portion divided by a plurality of notches along the length direction. A tapered part is formed at the end of the pull rod so that the outer diameter increases toward the tip, and the holding member can be detachably attached to the machine tool connecting member. The pull rod is capable of moving back and forth along its length with respect to the holding member, and the tapered portion of the draw rod enters the divided portion of the holding member, thereby expanding the divided portion of the holding member. It is pressed against the side wall of the circular hole in the gear material.

The gear material attachment method of the present invention includes installing the gear material holding device described above in a machine tool, fitting the circular hole of the gear material into the hollow cylindrical part of the gear material, and moving the pull rod against the holding member. Attach the gear material to the machine tool by moving the pull rod lengthwise so that the tapered portion of the drawbar enters the split portion of the holding member, expanding the split portion and pressing it against the side wall of the circular hole in the gear material. .

The gear material holding device and gear material attaching method of the present invention allow the gear material to be easily attached to and removed from the machine tool, and moreover, the rotating shaft of the machine tool can be accurately positioned at the center of the hole in the center of the gear material. They can be installed together to achieve precision machining.

It is a sectional view showing a material holding device for gears. It is a sectional view showing a machine tool connection member. FIG. It is a sectional view showing a holding member. It is a front view of the same. FIG. FIG. 3 is a front view of the pull rod. FIG. FIG. 3 is an enlarged cross-sectional view showing a hollow cylindrical portion of the holding member. FIG. 3 is a cross-sectional view showing a hardened area. It is a sectional view showing an example of a gear material attachment method. It is a sectional view showing the 2nd example of a material holding device for gears.

Embodiments for carrying out the present invention will be described in detail based on the drawings. FIG. 1 is a sectional view showing a gear material holding device. The gear material holding device 1 is a device for holding gear material x having a circular hole x1 in the center. It has a machine tool connecting member 2 connected to a machine tool y, a holding member 3, and a pull rod 4. The car material holding device 1 can be applied to materials for gears of various shapes, for example, in addition to cylindrical materials for spur gears, it can also be applied to materials for bevel gears that have a truncated conical shape. can also be applied. This example shows a gear material for a spiral bevel gear. In such a shape, the side surface portion with the maximum diameter is small, making it difficult to grip it from the outside with a conventional chuck, and if it is pinched from above and below, it becomes impossible to process the truncated conical portion at the top.

FIG. 2 is a sectional view showing the machine tool connecting member, and FIG. 3 is a plan view thereof. The machine tool used in the present invention can be any of various general machine tools used for manufacturing or pre-processing gears. These machine tools have a member y that rotates by being driven by a drive source (not shown) such as a motor, and are provided with a portion to which a member such as a chuck for holding gear material is attached. In this example, a truncated cone-shaped depression that opens upward is formed, and the machine tool connecting member 2 is fixed therein. If the machine tool itself does not have a rotating part of such an appropriate shape, one may be created as appropriate to replace the rotating part of the original machine tool.

The outer shape of the machine tool connecting member 2 is formed in a shape that allows it to be attached to a rotating part of a machine tool. The outer side surface has a tapered portion, and this surface contacts the surface of the truncated cone-shaped recess of the machine tool. Further, a hollow portion is formed in the center of the machine tool connecting member 2 along the central axis. Particularly near the upper end, the hollow portion is a conical recess that opens upward. Preferably, the tapered surface on the outer side surface and the surface of the conical recess in the center are entirely polished. Polishing improves the connection between the machine tool and the holding member described below, and reduces backlash when the machine tool is rotated for machining. In this way, more precise machining can be achieved.

Next, the holding member 3 will be explained. FIG. 4 is a sectional view showing the holding member, FIG. 5 is a front view thereof, and FIG. 6 is a plan view thereof. The holding member 3 also has a hollow shape at the center. The base has a generally truncated conical outer shape, and has a tapered surface that engages with the recess of the machine tool connecting member 2. In this example, a stronger taper angle is formed on the outer periphery of the lower end to facilitate insertion.

A hollow cylindrical part 5 is formed in the upper part of the holding member 3. Its outer shape corresponds to the shape of the circular hole in the gear material to be held, but is slightly smaller. At least the distal end portion of the hollow cylindrical portion 5 is formed with a divided portion divided by a plurality of notches 6 along the length direction. The number of cuts, that is, the number of divisions, is preferably 3 or more and 6 or less, and particularly preferably divided into four equal parts by four cuts 6 as shown in FIG. In addition, the depth of the cut 6 is determined so that when the tip of the pull rod 4 is lowered, an appropriate deflection occurs, that is, the split part deflects outward to fit inside the circular hole in the gear material. It only needs to be set so as to be in contact with the wall surface and to be pressed against the inner wall surface with sufficient strength. If this condition is satisfied, the cut 6 may be provided only near the upper end of the hollow cylindrical portion 5, but in this example, the cut 6 is provided over the entire length of the hollow cylindrical portion 5.

The inner wall surface of the upper end of the hollow cylindrical portion 5 is formed with a tapered surface that becomes thinner toward the top.

FIG. 7 is a front view showing the pull rod, and FIG. 8 is a plan view thereof. The lower part of the pull rod 4 is a round bar-shaped member, and the outer diameter of that portion is smaller than the diameter of the hollow hole of the holding member 3, so that even if it is inserted into the hollow hole of the holding member 3, the holding member A gap is created between the inner wall of No. 3 and the inner wall of No. 3.

The upper part of the draw rod 4 is formed with a tapered part whose outer diameter increases toward the tip. This taper angle roughly matches the taper angle of the inner wall surface of the upper end portion of the hollow cylindrical portion 5 . As will be described later, this tapered portion causes the divided portions of the hollow cylindrical portion 5 to be spread apart when the pull rod 4 is lowered. Here, a large taper angle is provided, for example, set at 75° with respect to the axial direction, in order to allow the divided portion to be widened by a small amount of movement. Further, the diameter at the upper end surface is larger than the inner diameter of the hollow cylindrical portion 5.

The lower end of the draw rod 4 is formed with a male thread. Further, a tool insertion hole 7 is formed on the top surface into which the tip of a fastening tool such as a screwdriver or hex wrench is inserted. In this example, a cross recess for a Phillips screwdriver is provided.

A rod-shaped connecting member 8 is provided below the pull rod 4. A female thread is provided at the center of the upper end of the connecting member 8 . By engaging the male threaded portion of the pull rod 4 with this female threaded portion, the connecting member 8 and the draw rod 4 are connected. At this time, a gap is formed between the upper end of the connecting member 8 and the lower end of the holding member.

Furthermore, an engaging portion such as a male thread is formed at the lower end of the connecting member 8 so that it can be connected to the driving member 9. Here, the drive member 9 is a member that moves the pull rod 4 and the connecting member 8 back and forth along the axial direction by a drive source such as a hydraulic device, and furthermore, the driving member 9 is a member that moves the pull rod 4 and the connecting member 8 back and forth in the axial direction with respect to the main body of the machine tool. 8 is rotatably supported. Many machine tools are often equipped with such a drive member 9, and in that case, it is sufficient to use it. Further, if a suitable driving member is not provided, it may be separately prepared and attached. Further, the connecting member 8 may be set a little shorter so that a gap is created between it and the driving member 9, and the adjustment may be made using a washer-like spacer 10 at the time of connection.

The main members of the gear material holding device 1, such as the machine tool connecting member, the holding member, and the pull rod, are made of strong materials. Among metal materials, steel is preferred because it has high strength and is easily available. In particular, chromium molybdenum steel is suitable for the holding member 3 and the draw rod 4. In this example, JIS G4053 alloy steel for mechanical structures classified as SCM415 is used. This is a material suitable for hardening, and in this example, carburizing and hardening is performed.

The machine tool connecting member 2, the holding member 3, and the tension rod 4 are preferably hardened. FIG. 10 shows the locations where hardening is performed.
It is particularly preferable to harden the tapered portion Q1 of the draw rod 4 and the tapered surface Q2 of the hollow cylindrical portion 5. Since these parts are pressed against each other with strong force, wear tends to progress. By hardening, it is possible to suppress wear and achieve a long service life, and by maintaining the precision of the shape, the gear material can be held accurately.
Further, in the divided portion 5, all portions other than the tapered surface Q2 at the tip may be hardened. In this case, it is preferable to first create a cylindrical member, then harden it, and then make cuts along its length. By performing hardening when the shape is cylindrical, deformation during hardening can be reduced and an accurate shape can be obtained. This hardening improves the strength and rigidity of the divided portion 5, increases its durability, and provides elasticity more suitable for opening and closing the divided portion 5 by vertical movement of the pull rod 4.
It is preferable that the outer surface Q3 of the hollow cylindrical portion 5 of the holding member 3 and the surface of the base portion Q4 following this also be hardened. By reinforcing this part, the correct shape can be maintained and the gear material can be accurately secured.
It is preferable that the tapered portion Q5 at the base of the holding member 3 and the conical recessed portion Q6 in the hollow portion of the machine tool connecting member 2 that engages with the tapered portion Q5 also be hardened. These portions also contact each other to strengthen and reduce wear while maintaining accurate alignment and engagement.
In addition, it is preferable that the fitting tolerance between the holding member 3 and the machine tool connecting member 2 is H8 or more according to JIS. As a result, accurate rotation with small runout can be given to the gear material during machining, and a highly accurate gear can be obtained.
Further, it is preferable that a portion 3a having a cylindrical side surface shape is formed on the tapered portion Q5 at the base of the holding member 3. This portion 3a can be gripped when attaching to and detaching from the machine tool connecting member 2 or a rotating part of a machine tool as described later.

Next, the function of the gear material holding device and the method of attaching gear material will be explained. First, the gear material holding device 1 is assembled. The gear material holding device 1 is divided into a machine tool connecting member 2, a holding member 3, and a pull rod 4, and further includes a connecting member 8 in this example. Multiple types of holding members 3 are prepared depending on the shape of the gear material x that can be used, especially the inner diameter and depth of the circular hole x1, and the material for the gear at that time is selected from among them. A holding member suitable for x can be selected. Further, a plurality of types of pull rods 4 and connecting members 8 can be prepared in the same manner. In this way, by combining the members of the respective parts, various types of gears can be manufactured by replacing only a part of the gear material holding device 1 without replacing the entire gear material holding device 1.

The gear material holding device 1 is attached to the rotating part y of the machine tool, and the connecting member 8 is connected to the driving member 9. Then, the gear material x is attached to the holding member. FIG. 9 is an enlarged sectional view showing the hollow cylindrical portion of the holding member. Place the pull rod 4 in the upper position as shown in FIG. 9(a). At this time, the upper end of the pull rod 4 is either separated from the upper end of the hollow cylindrical portion 5 or is in weak contact with the upper end. The dividing part of the hollow cylindrical part 5 is not expanded, so that the circular hole x1 of the gear material x can be fitted into the hollow cylindrical part 5.

Then, the drive member 9 is actuated to pull the pull rod 4 downward. As shown in FIG. 9(b), the upper end of the pull rod 4 is lowered, thereby applying an outward force to the upper end of the divided portion of the hollow cylindrical portion 5. The upper end of the divided portion is pushed outward while being bent outward, and is pressed against the inner surface x2 of the circular hole x1 of the gear material x. In this way, the gear material x is firmly fixed to the holding member 3. At this time, the center position of the circular hole x1 exactly matches the position of the central axis of the holding member 3. The upper end of the pull rod 4 also applies a downward force to the upper end of the pull rod 4. Thereby, the gear material holding device 1 is firmly fixed to the rotating part y of the machine tool.

As described above, the gear material x can be attached by simply fitting the circular hole x1 of the gear material x into the hollow cylindrical portion 5 and pulling down the pull rod 4 using the drive member 9. Once the gear material x has been attached, the rotating part y of the machine tool can be rotated to perform necessary processing such as pre-processing and gear cutting. The outer periphery of the gear material x is completely open, and there is no obstacle to the machining operation. Even when the material has a complicated shape, such as the gear material for the spiral bevel gear in this example, it can be fixed easily and reliably, and all the outer surfaces can be freely processed. As long as the inner diameter of the circular hole x1 corresponds to the outer shape of the hollow cylindrical portion 5, gear material of any outer shape can be held.

When pre-processing is performed, the finished outer shape of the gear material x may be rough, and the center position of the outer periphery may not match the center position of the circular hole. According to the gear material holding device and the gear material attaching method of the present invention, the rotation center of the rotating portion y of the machine tool coincides with the center position of the circular hole x1. Therefore, the tooth surfaces of the final gear rotate accurately around the central axis.

When the necessary processing is completed, the rotation of the rotating part y of the machine tool is stopped. The drive member 9 is actuated to move the pull rod 4 upward, returning it to the state shown in FIG. 9(a). The upper end of the division is reduced and separated from the inner surface x2 of the circular hole x1 of the gear material x. In this way, the gear material x after processing can be easily removed.

As described above, the holding member can be attached to and detached from the machine tool connecting member by vertical movement of the pull rod 4 by the operation of the drive member 9. There is no need to use tools such as screwdrivers or spanners.

In a computer-controlled machine tool, the operation of the drive member 9 can also be automatically controlled. Therefore, by automatically controlling the vertical movement of the drive member 9, the attachment and detachment of the gear material x can be automated, the work can be automated and speeded up, and safety can be improved.

FIG. 11 is a sectional view showing an example of a method for attaching gear material. Depending on the gear material, the inside of the center hole may also be machined. In particular, there are cases in which a counterboring process is applied to the center part in a shape that opens outward. In this case, counterboring is performed while the cutting blade enters the center. In FIG. 11, the portions to be counterbored are indicated by hatching. In this example, the shapes of the tip of the pull rod and the tip of the empty cylindrical portion of the holding member are set so that they are located deeper than the depth of the counterbore. Hold the gear material in this position. As a result, the pull rod and the holding member do not interfere with the cutting blade, so counterboring can be performed safely and easily.

FIG. 12 is a sectional view showing a second example of a gear material holding device. In this example, unlike the example shown in FIG. 1, the holding member 3 is directly attached to the rotating part y of the machine tool. Some machine tools are not equipped with a rotating part y suitable for connecting the machine tool connecting member 2 as shown in FIG. In such a case, it is possible to create a rotating part y as shown in FIG. 1 and replace it with the original rotating part, but in this example, as shown in FIG. is formed along the central axis at the center, and the hollow section near the upper end is a conical recess that opens upward. This corresponds to the conical recess provided in the center of the machine tool connecting member 2 in the example of FIG. By mounting the holding member 3 in this conical recess, the holding member 3 can be rotatably attached to the machine tool. The tapered portion of the holding member 3 may be provided over a large range on the upper side, and in this case, a part of the tapered portion of the holding member 3 protrudes above the conical depression in the hollow part of the rotating part y of the machine tool. state.

It is preferable to harden the tapered portion Q5 at the base of the holding member 3 and the conical depression portion Q6 in the hollow portion of the rotating portion y of the machine tool that engages with the tapered portion Q5. Furthermore, it is preferable that the recessed portion Q6 is also polished. These portions also contact each other to strengthen and reduce wear while maintaining accurate alignment and engagement. As a result, accurate rotation with small runout can be given to the gear material during machining, and a highly accurate gear can be obtained.

1. Gear material holding device 2. Machine tool connection member 3. Holding member 4. Pull rod 5. Hollow cylindrical part6. Notch 8. Connecting member 9. Drive member x. Gear material x1. Circular hole x2. Inner wall of circular hole y. Rotating parts of machine tools

Claims (5)

A device for rotatably holding gear material with a circular hole in the center on a machine tool,
a holding member having a hollow cylindrical portion in contact with the side wall of the circular hole of the gear material;
a pull rod inserted into the hollow cylindrical portion of the holding member;
A divided portion is formed at the end of the hollow cylindrical portion of the holding member by a plurality of notches along the length,
The end of the pull rod has a tapered part that increases in outer diameter toward the tip.
The holding member can be detachably attached to the machine tool,
The draw rod is capable of moving back and forth along its length with respect to the holding member;
A gear material holding device is installed on a machine tool in which the tapered part of the pull rod enters the divided part of the holding member, thereby expanding the divided part of the holding member and pressing it against the side wall of the circular hole in the gear material. death,
Insert the circular hole of the gear material into the hollow cylindrical part of the holding member,
by moving the drawbar longitudinally relative to the retaining member such that the tapered portion of the drawbar enters the split in the retaining member, enlarging the split and pressing against the side wall of the circular hole in the gear material; A gear material attachment method for attaching gear material to a machine tool,
The material for gears has a counterbore in the center, and the tip of the pull rod and the tip of the empty cylindrical part of the holding member are located inside the circular hole deeper than the depth of the counterbore, and the material for gears is processed by counterbore processing. Material attachment method for gears that hold. A device for holding gear material with a circular hole in the center,
a machine tool connecting member connected to the machine tool;
a holding member having a hollow cylindrical portion in contact with the side wall of the circular hole of the gear material;
a pull rod inserted into the hollow cylindrical portion of the holding member;
A divided portion is formed at the end of the hollow cylindrical portion of the holding member by a plurality of notches along the length,
The end of the pull rod has a tapered part that increases in outer diameter toward the tip.
The holding member can be detachably attached to the machine tool connecting member,
The draw rod is capable of moving back and forth along its length with respect to the holding member;
A gear material holding device for a machine tool is provided in which the tapered part of the pull rod enters the divided part of the holding member so that the divided part of the holding member expands and is pressed against the side wall of a circular hole in the gear material. installed,
Insert the circular hole of the gear material into the hollow cylindrical part of the holding member,
by moving the drawbar longitudinally relative to the retaining member such that the tapered portion of the drawbar enters the split in the retaining member, enlarging the split and pressing against the side wall of the circular hole in the gear material; A gear material attachment method for attaching gear material to a machine tool,
The material for gears has a counterbore in the center, and the tip of the pull rod and the tip of the empty cylindrical part of the holding member are located inside the circular hole deeper than the depth of the counterbore, and the material for gears is processed by counterbore processing. How to attach material for gears to hold. The holding member can be detachably attached to the rotating part of the machine tool.
The rotating part of the machine tool is made of steel, and the center of the rotating part of the machine tool has a hollow part formed along the central axis, and near the upper end, the hollow part is a conical depression that opens upward. It has become,
The base of the holding member is provided with a tapered surface shaped to engage with the conical recess of the mounting member,
2. The method for attaching gear material according to claim 1, wherein the surface of the conical recess of the rotating part of the machine tool is hardened. The holding member and the pull rod are made of steel, and the inner wall surface of the distal end of the divided portion of the hollow cylindrical portion is formed with a tapered surface that becomes thinner toward the tip. 3. The gear material attachment method according to claim 1, wherein the tapered portion and the tapered surface of the hollow cylindrical portion are hardened. 5. The method for attaching gear materials according to claim 3, wherein the holding member and the pull rod are made of chromium molybdenum steel and are carburized and hardened.

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