JP4378377B2 - Tool holding device for tools with straight shank - Google Patents

Description

  The present invention relates to a tool holding device provided for holding a tool in a tool storage magazine of an automatic machine tool that grips a tool having a straight shank portion with a collet of a main shaft.

  In an automatic machine tool such as an NC machine tool, workpieces of various shapes are processed or manufactured by making full use of various tools. For this reason, in the machine tool, a tool storage magazine for storing a large number of tools is indispensable. In this tool storage magazine, a large number of tool holding devices are usually provided to store a large number of tools, and a tool necessary for manufacturing is automatically selected from the tool holding device and replaced.

  In such a tool holding device, a bottom surface or a stopper is provided in a tool insertion hole, and a tip portion which is a tool cutting edge is temporarily supported by the bottom surface or the like, and then side-locked from the side with respect to the tool axis direction. There is a tool holding device that presses a tool straight shank portion using a pin, slides the tool to a side wall of a tool insertion hole facing the side lock pin, positions and holds the tool.

  In such a type of tool holding device, due to the presence of a bottom surface or a stopper, the distance from the bottom surface or the like to the side lock pin has to be constant. Therefore, a tool that is so long that the side lock pin hits the taper portion or the blade portion of the tool cannot be properly held and cannot be stored in the tool holding device. As a result, when a tool having a certain neck length or longer is required during the manufacturing process, the automatic manufacturing process needs to be temporarily stopped and the operator himself / herself needs to change the tool. Therefore, there arises a problem that continuous operation cannot be performed until the final production of the workpiece is completed.

  Furthermore, even if the tool has a length under the neck that can be stored in the tool holder, when the side lock pin presses the tool, the tool blade tip will be caught by the bottom surface or stopper, and the tool will not slide properly. It may be retained. In such a case, the accuracy of gripping the spindle on the collet is significantly reduced, or in the worst case, the collet cannot automatically grip the tool.

  In addition, a load may be applied to the tool cutting edge in contact with the bottom surface or the like when the side lock pin presses the tool. Therefore, especially when using a small-diameter tool, the cutting edge of the blade part may be chipped or broken. Naturally, normal and appropriate machining cannot be performed in a state where the blade part is abnormal, and thus it is necessary to stop the manufacturing apparatus and replace it with a normal tool. Also, if the product is processed without detecting that the blade part of the tool is abnormal, it may be one of the causes for producing a defective product.

  Patent Documents 1 and 2 disclose an automatic tool changer that does not have a bottom surface for receiving a tool edge. In such a tool changer, the above-described problems do not occur, but automatic tool change is performed unless additional machining or a retaining ring or ring is attached to the tool for supporting or positioning the tool. Cannot be used, and the tool cannot be used as it is on the market. In addition, when a product is processed with a tool equipped with a retaining ring, a ring, etc., the retaining ring, the ring, etc., that are attached when the tool rotates may move, and the position where the tool is supported may change.

Japanese Patent Laid-Open No. 05-277867 Japanese Patent Application Laid-Open No. 08-174364

  In light of the above-mentioned problems, the present invention is different in length under the neck in the form as it is marketed without any additional work on the tool or attachment of a retaining ring or a ring for supporting and positioning the tool. A tool holding device that can hold a tool, and further facilitates handling by eliminating chipping and breakage of the tool and ensuring the proper position and posture of the tool. It is a problem to provide.

The above problem is achieved by using a tool holder provided with a tool insertion hole configured as a through hole for inserting a tool in a vertical direction, and a side lock pin acting toward the center of the cross section of the tool insertion hole. A side lock mechanism for positioning the tool by pressing the straight shank portion of the tool against the lateral wall of the tool insertion hole from the lateral direction with respect to the vertical direction, and inside the tool insertion hole, It is a shoulder for contacting only the taper portion of the tool and supporting the tool, and is located on the lower side in the vertical direction of the side lock pin and from the side where the side lock pin is provided. This is solved with a tool holding device in which a shoulder projecting radially inward is provided .

The tool through hole is configured to have a diameter larger than the diameter of the straight shank portion so that a tool can be inserted. In other words, the tools that can be housed in the tool holding device of the present invention are limited to tools whose blade part diameter is smaller than the straight shank part diameter.

The amount of protrusion of the shoulder that protrudes radially inward of the tool through-hole is adjusted by adjusting the amount of protrusion so that the tool edge does not touch the shoulder as well as the tool holder when the tool is inserted. The In addition, the tool taper must also be configured to be supported on the shoulder. That is, the maximum protrusion amount of the shoulder portion in the radial direction of the tool through hole needs to be smaller than half of the value obtained by subtracting the diameter of the tool edge from the diameter of the tool insertion hole into which the tool is inserted. It is necessary to make it larger than half the value obtained by subtracting the diameter of the tool straight shank from the diameter of the insertion hole. More specifically, assuming that the diameter of the tool insertion hole is D, the diameter of the tool edge is d, the diameter of the straight shank portion of the tool is d ′, and the maximum protrusion amount of the shoulder is P, The relationship is true.
(Dd ') / 2 <P <(Dd) / 2
In this way, by adjusting the amount of protrusion of the shoulder, the tool edge does not contact the tool holder, especially the shoulder, and only the taper of the tool is supported by the shoulder during automatic tool insertion. It becomes a structure to be.

  The position in the vertical direction (longitudinal direction of the tool) where the shoulder is provided inside the tool insertion hole is determined by the size and position of the side lock mechanism with reference to the straight shank portion and the taper portion of the tool. That is, the side lock mechanism provided in the tool holding device must be configured so as to push at least a part of the straight shank portion of the tool and be adjusted so that the side lock pin does not contact the taper portion or the blade portion of the tool. Don't be.

  In order to achieve this object, it is preferable that the position of the shoulder supporting the tool and the amount of protrusion be adjusted so as to support the maximum diameter position of the tapered portion as much as possible, that is, the position as close as possible to the straight shank portion. By setting the vertical position and the amount of protrusion of the shoulder in this way, the diameter of the blade edge of the tool that can be stored can be made as large as possible, and the side lock pin above the shoulder should act. It becomes possible to have as many straight shank portions as possible in the space.

  A side lock mechanism is provided on the shoulder side of the tool insertion hole in the tool holding device in order to prevent the tool from rotating around the shoulder and being held obliquely when the side lock pin acts. There must be. In addition, the side lock pin must be operated toward the center of the cross section of the tool insertion hole. With this configuration, when the tool is pressed by the side lock pin, the tool is not held obliquely with the shoulder as a fulcrum, and the outer peripheral curved surface of the tool's straight shank is always positioned in the tool insertion hole. It will press against the same outer peripheral curved surface, and appropriate positioning of the tool will be ensured. If proper positioning is performed, the tool can also achieve a proper posture for tool change (a posture in which the axis of the tool is parallel to the vertical direction).

  The positioning of the tool by pressing the side lock pin may act only when the tool is transferred to and from the spindle collet, or may always act while the tool is stored in the tool holder.

In addition, the side lock mechanism may be installed in each tool holder in the tool storage magazine, or may be installed at an arbitrary position by one or a plurality smaller than the number of tool holders. In the latter case, it is necessary to perform an indexing operation of an arbitrary tool holder, and at that time, the restraint of the tool by the side lock pin needs to be released.

  With this configuration, the tool to be held inserted in the vertical direction is supported by the shoulder only at the tapered portion by its own weight. In addition, since the bottom surface and the like are omitted, a long tool under the neck protrudes from the lower end surface of the tool holding device, but even a tool having a different length under the neck can be stored. become.

  Also, since the tool stored in the tool storage device is always supported at the same taper position when removed from the collet of the spindle, the straight shank portion of the tool is laterally locked with the side lock pin from the vertical direction. When pressed, the outer peripheral curved surface of the straight shank portion of the tool is uniquely pressed against the horizontal wall that forms the outer periphery of the tool insertion hole, so that appropriate positioning is achieved. Therefore, the tool can be always held in the tool holder at the same position and posture when changing the tool.

  Of course, the tool must have a structure that does not come into contact with the cross-sectional shape of the through hole vertically below the shoulder. As long as the tool is not in contact, the shape of the through hole on the lower side in the vertical direction from the shoulder portion may take any form. For example, the cross-sectional shape can be a long hole shape or an arbitrary shape.

  According to the present invention, for supporting and positioning the tool, it is not necessary to perform additional machining or mounting of a retaining ring, a ring, or the like on the tool, and a tool having a different neck length in a commercially available shape is used as a tool holding device. In addition, since the cutting edge of the tool does not contact the tool holding device, the tool can be automatically changed without chipping or breaking the cutting edge. In addition, the side lock pin can always hold the straight shank of the tool properly against the lateral wall facing the shoulder that supports the tool, so that the tool is always positioned in the same position and orientation, and the tool axis Can be directed in the vertical direction, so that the reliability of the gripping accuracy and the repeated replacement accuracy at the time of automatic tool change are increased.

  Embodiments of the present invention will be specifically described with reference to the drawings.

FIG. 1 schematically shows an example of a tool holding device according to the present invention in a cross-sectional view. As can be seen from FIG. 1, the tool insertion hole (4) of the present embodiment is configured as a through hole that penetrates the tool holder (1), while forming a shoulder (5) It is composed of two holes whose center axes are shifted to the side facing the side lock pin, and facing each other in the vertical direction in which the tool is inserted . The side lock pin (2) shown in FIG. 1 is a commonly known side lock pin (2), and a hole (8) for inserting the side lock pin (2) is a tool insertion hole (4). It is provided in the direction orthogonal to In the present embodiment, the side lock pin (2) having a flat tip is used, but the side lock pin that can be used in the present invention is not limited to this shape. Moreover, since the taper part (7) of a tool is supported by the shoulder part (5) provided in the side lock pin side so that it can see from FIG. 1, the straight shank part of a tool is shoulder part ( When pressing against the horizontal wall which is the outer peripheral curved surface of the tool insertion hole (4) facing 5), the shoulder (5) serves as a fulcrum and the tool does not tilt, and the tool is held in an appropriate posture.

  FIG. 2 shows a view of the tool holding device of FIG. 1 as viewed from below. As can be seen from the drawing, the center axis of the counter hole is shifted to form a through hole, whereby the shoulder (5) of the tool holder is formed in a crescent shape. The maximum protrusion amount (P) of the shoulder (5) in the radial direction of the tool insertion hole is equal to the deviation amount of the central axis of the opposed hole, and when the tool is inserted from above the tool holder (1) with the collet of the main shaft. The blade part does not come into contact with the shoulder part (5) as well as the tool holder (1), and only the tapered part (7) and the shoulder part (5) of the tool (3) come into contact and are supported. Configured.

  In the embodiment of FIG. 1, the position of the shoulder (5) in the tool insertion hole (4) in the vertical direction (longitudinal direction of the tool) is such that only the straight shank portion of the tool (3) is attached to the side lock pin (2). Can be seen to be configured to hold. However, in carrying out the present invention, it is not necessary for the entire pressing surface of the side lock pin (2) to press the straight shank portion as in this embodiment. If the side lock pin (2) is configured so as to hold at least a part of the straight shank portion and prevent the taper portion (7) or the blade portion of the tool from contacting the side lock pin (2), Aim can be achieved.

  3-5 schematically illustrate the process by which the tool (3) is housed in the tool holder, which is the exemplary embodiment described in FIG. FIG. 3 shows a state in which the tool (3) gripped by the collet of the spindle approaches the tool holding device from above. Arrow X indicates the direction in which the collet of the spindle moves to insert the tool.

  FIG. 4 shows a state in which the tool (3) is positioned by the side lock pin (2) after the tapered portion (7) is supported by the shoulder (5) in the tool insertion hole (4). As is apparent from the figure, when the tool (3) is inserted into the tool insertion hole, the amount of protrusion of the shoulder (5) is adjusted so as not to contact the cutting edge of the tool (3). Since the side lock pin (2) holds the straight shank of the tool against the lateral wall that is the outer periphery of the tool insertion hole (4) facing the shoulder (5), the axis of the tool (3) is appropriate in parallel with the vertical direction. Can be held in.

  FIG. 5 shows a state in which the restriction of the tool by the side lock pin (2) is released. Although it is possible to store the tool in the tool holder in the state shown in FIG. 5, in this case, when the collet of the spindle comes to receive the stored tool (3) in the automatic tool changing process. Again, it is necessary to operate the side lock pin (2) and perform proper positioning.

  FIG. 6 shows a schematic view of a conventional tool holding device that supports the tool edge on the bottom surface. When a tool having a neck length longer than the neck length of the tool (3) shown in the figure is to be stored, the side lock pin (2) may not act on the straight shank portion of the tool (3). I can see that. It will also be understood that when the side lock pin acts, the tip of the cutting edge may be caught on the bottom surface of the tool holding device.

  As apparent from FIGS. 4 and 5, the tool (3) housed in the tool holding device (1) of the present invention has a cutting edge protruding from the tool holding device using the through-hole (4). Even a long tool can be stored in the tool holding device.

  Moreover, since the cutting edge does not contact any part of the tool holding device when the tool is housed in the tool holding device and when it is pulled out from the tool holding device, the straight shank portion of the tool and Even if a load is applied to the upper surface, no force is applied to the cutting edge, and the chipping or breakage of the cutting edge due to automatic tool change does not occur.

  FIG. 7 shows another embodiment of the present invention. In the embodiment of FIG. 7, it can be seen that the cross-sectional shape of the through hole (4) below the shoulder (5) is a long hole shape. Thus, in order to achieve the object of the present invention, the cross-sectional shape on the lower side in the vertical direction than the shoulder portion (5) is not a big problem. That is, when the tool (3) is inserted / removed into / from the tool insertion hole (4), only the tapered portion (7) of the tool (3) comes into contact with the tool holder (1). ) Is provided on the side wall on the side lock pin side inside the tool insertion hole, and after the collet of the spindle has removed the tool (3), the tool (3) is inserted by acting only on the straight shank of the tool. If there is a side lock mechanism for pressing the lateral wall (6) of the hole (4), the object of the present invention can be achieved.

It is a schematic sectional drawing which shows an example of the tool holding apparatus in this invention. It is a bottom view of the tool holding apparatus of FIG. It is sectional drawing which showed roughly one process at the time of accommodating a tool in the tool holding apparatus of this invention. It is sectional drawing which showed roughly one process at the time of accommodating a tool in the tool holding apparatus of this invention. It is sectional drawing which showed roughly one process at the time of accommodating a tool in the tool holding apparatus of this invention. It is a schematic sectional drawing of the conventional type tool holding apparatus. It is the schematic sectional drawing and another bottom view of another embodiment of the tool holding device in the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tool holder 2 Side lock pin 3 Tool with straight shank shape 4 Tool insertion hole 5 Shoulder part 6 Side wall of the tool insertion hole facing the side lock pin 7 Tool taper part 8 Side lock pin insertion hole 9 Long hole shape lower tool insertion hole

Claims (2)

In a tool holding device used to hold a tool (3) in a tool storage magazine provided in an automatic machine tool that grips a tool (3) having a straight shank portion with a collet of a main spindle,
The tool holding device includes a tool holder (1) provided with a tool insertion hole (4) configured as a through hole for inserting a tool (3) in a vertical direction, and a cross section of the tool insertion hole (4). By using the side lock pin (2) acting toward the center, the straight shank portion of the tool (3) is pressed against the lateral wall of the tool insertion hole (4) from the lateral direction with respect to the vertical direction. A side lock mechanism for positioning (3),
Inside the tool insertion hole (4) is a shoulder (5) for supporting the tool (3) in contact with only the tapered portion (7) of the tool (3), A tool provided with a shoulder (5) that protrudes radially inward of the tool insertion hole (4) from a side below the lock pin (2) in the vertical direction and from the side where the side lock pin (2) is provided. Holding device. In order to form the shoulder portion (5) , the through hole which is the tool insertion hole (4) is two holes whose center axes are shifted in a direction facing the side lock pin (2) , The tool holding device according to claim 1 , comprising two holes facing each other in a vertical direction in which the tool is inserted .

Images