Shrink-fitting apparatus and shrink-fitting method

Abstract

To improve the efficiency of tool installation work using shrink fitting. [Solution] The shrink-fitting device 10 includes a heating device 11 for heating a cylindrical holder 2, a measuring device 13 for performing a first measurement to measure the relative position of a tool 1 inserted into the holder 2 with respect to the holder 2 while the holder 2 is heated by the heating device 11, and an adjustment device 12 for adjusting the relative position based on the result of the first measurement by the measuring device 13 while the holder is heated.

Description

Technical Field

[0001] The present disclosure relates to a shrink-fitting device and a shrink-fitting method.

Background Art

[0002] In machining, machining such as cutting is performed using a tool such as an end mill. In an NC machine such as a machining center, the tool is used in a state where it is set in a holder. For example, as disclosed in Patent Document 1, shrink-fitting is widely used as a method for attaching a tool to a holder.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the work of attaching a tool using shrink-fitting, it is necessary to attach the tool to the holder so that the protruding length, which is the length of the part of the tool that protrudes from the holder, falls within a specified range. And it is desired to improve the efficiency of such an attachment operation.

[0005] An object of the present disclosure is to provide a shrink-fitting device and a shrink-fitting method capable of improving the efficiency of the work of attaching a tool using shrink-fitting.

Means for Solving the Problems

[0006] In order to solve the above problems, the shrink-fitting device of the present disclosure includes a heating device that heats a cylindrical holder, a measuring device that performs a first measurement of measuring the relative position of a tool inserted into the holder with respect to the holder in a heating state where the holder is heated by the heating device, and an adjusting device that adjusts the relative position based on the result of the first measurement by the measuring device in the heating state.

[0007] The measuring device may perform a second measurement of the relative position after the relative position has been adjusted by the adjustment device, while the holder is in an unheated state and not heated by the heating device.

[0008] The adjustment device may include a shaft inserted into a holder and a drive device that moves the tool by moving the shaft while the shaft is in contact with the tool.

[0009] The adjustment device may include a first detection device for detecting the contact state.

[0010] A second detection device may be provided to detect information about the tool other than its relative position.

[0011] To solve the above problems, the shrink-fitting method of the present disclosure includes: a first step of heating a cylindrical holder with a heating device; a second step of performing a first measurement with a measuring device to measure the relative position of a tool inserted into the holder with respect to the holder while the holder is heated by the heating device; and a third step of adjusting the relative position with an adjustment device based on the result of the first measurement by the measuring device while the holder is heated.

[0012] To solve the above problems, the shrink-fitting apparatus of this disclosure comprises a measuring device that performs a third measurement to measure the total length of a tool, a heating device that heats a cylindrical holder, and an adjustment device that adjusts the relative position of the tool inserted into the holder with respect to the holder based on the result of the third measurement by the measuring device while the holder is heated by the heating device.

[0013] To solve the above problems, the shrink-fitting method of the present disclosure includes a first step of performing a third measurement to measure the total length of the tool using a measuring device, a second step of heating a cylindrical holder with a heating device, and a third step of adjusting the relative position of the tool inserted into the holder with respect to the holder using an adjustment device, based on the result of the third measurement by the measuring device while the holder is heated by the heating device. [Effects of the Invention]

[0014] According to this disclosure, the efficiency of tool installation work using shrink fitting can be improved. [Brief explanation of the drawing]

[0015] [Figure 1] Figure 1 is a schematic diagram showing the configuration of a tool and holder according to an embodiment of this disclosure. [Figure 2] Figure 2 is a schematic diagram showing the configuration of a shrink-fitting apparatus according to an embodiment of the present disclosure. [Figure 3] Figure 3 shows the first step of the shrink-fitting method according to the embodiment of this disclosure. [Figure 4] Figure 4 shows the second step of the shrink-fitting method according to the embodiment of this disclosure. [Figure 5] Figure 5 shows the third step of the shrink-fitting method according to the embodiment of this disclosure. [Figure 6] Figure 6 shows the fourth step of the shrink-fitting method according to the embodiment of this disclosure. [Figure 7] Figure 7 is a schematic diagram showing the configuration of a shrink-fitting device according to the first modified example of this disclosure. [Figure 8] Figure 8 is a schematic diagram showing the configuration of a shrink-fitting device according to a second modified example of the present disclosure. [Figure 9] Figure 9 shows the first step of a shrink-fitting method using a shrink-fitting device according to the third modified example of this disclosure. [Figure 10] Figure 10 shows the second and third steps of a shrink-fitting method using a shrink-fitting device according to a third modified example of the present disclosure. [Modes for carrying out the invention]

[0016] Embodiments of the present disclosure will be described below with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for ease of understanding and do not limit the present disclosure unless otherwise specified. In the present specification and drawings, elements having substantially the same functions and configurations are denoted by the same reference numerals to avoid redundant description, and elements not directly related to the present disclosure are not shown.

[0017] FIG. 1 is a schematic diagram showing the configurations of a tool 1 and a holder 2 according to this embodiment. Hereinafter, as an example of the shrink fitting method according to this embodiment, an example in which the tool 1 is attached to the holder 2 by shrink fitting will be described. However, the shape and use of the tool 1 are not limited to the following examples. Also, the shape of the holder 2 is not limited to the following examples.

[0018] [[ID=,8]]The tool 1 is used in machining. For example, the tool 1 is used in an NC machine such as a machining center. For example, the tool 1 is an end mill or the like. The tool 1 has an elongated cylindrical shape. A cutting edge portion that is pressed against the machining target in machining is formed at the tip 1a of the tool 1. A circular surface orthogonal to the extending direction of the tool 1 is formed at the rear end 1b of the tool 1.

[0019] The holder 2 has a cylindrical shape. A through hole 2c that penetrates the holder 2 is formed in the holder 2 from the tip 2a to the rear end 2b. The through hole 2c extends coaxially with the central axis of the holder 2. The through hole 2c has a cylindrical shape. The holder 2 is formed of a metal material such as stainless steel, for example.

[0020] In an NC machine such as a machining center, the tool 1 is used in a state where it is set in the holder 2. In this embodiment, the tool 1 is attached to the holder 2 by shrink fitting.

[0021] In the installation process of tool 1 using shrink fitting, the holder 2 is heated first. If the holder 2 is not heated and its temperature is at room temperature, the inner diameter of the through hole 2c in the holder 2 is smaller than the outer diameter of tool 1. On the other hand, when the holder 2 is heated and its temperature rises, the holder 2 expands due to thermal expansion, causing the inner diameter of the through hole 2c in the holder 2 to become larger than the outer diameter of tool 1.

[0022] In the installation of tool 1 using shrink fitting, tool 1 is inserted into the through hole 2c of holder 2 while holder 2 is heated as shown. Specifically, as shown in Figure 1, tool 1 is inserted into the through hole 2c of holder 2 such that the rear end 1b of tool 1 is located inside the through hole 2c of holder 2, and the tip 1a of tool 1 protrudes outward from the tip 2a of holder 2. Subsequently, as the heating of holder 2 ends and the temperature of holder 2 decreases, holder 2 contracts, fixing tool 1 to holder 2.

[0023] In the installation process of tool 1 using shrink fitting, it is necessary to install tool 1 into holder 2 such that the protrusion length L, which is the length of the part of tool 1 that protrudes from holder 2, falls within a specified range. Furthermore, improving the efficiency of such installation work is desirable.

[0024] For example, in conventional installation work using shrink fitting, the total length of tool 1 is measured in advance at a location other than where the shrink fitting will be performed. Then, the shrink fitting is performed taking the results of this measurement into consideration. Specifically, during the shrink fitting process, the relative position of tool 1 with respect to holder 2 is adjusted, taking into consideration the results of the measurement performed in advance. After that, tool 1 and holder 2 are moved to a location other than where the shrink fitting will be performed, and the protrusion length L is measured at that location.

[0025] As described above, in conventional installation work using shrink fitting, the measurement is taken in a location separate from where the shrink fitting is performed, which increases the effort required to move tool 1. Furthermore, because the measurement is taken in a location separate from where the shrink fitting is performed, the reference point for adjusting the position of tool 1 and the reference point for measurement differ, resulting in a decrease in the installation accuracy of tool 1. In other words, it becomes difficult to keep the protrusion length L within the specified range.

[0026] According to the shrink-fitting method of this embodiment, as will be described later, the above-mentioned problems are resolved and the efficiency of the installation work of the tool 1 using shrink-fitting is improved.

[0027] The configuration of the shrink-fitting apparatus 10 according to this embodiment will be described below with reference to Figure 2.

[0028] In Figures 2 through 10, which are referenced below, the vertical direction of the paper corresponds to the vertical up-and-down direction. Hereafter, the vertical up-and-down direction will also be simply referred to as the up-and-down direction. Furthermore, the following description will explain an example in which shrink fitting is performed with tool 1 and holder 2 in a position extending in the vertical up-and-down direction. However, the position of tool 1 and holder 2 when shrink fitting is performed is not limited to this example.

[0029] Figure 2 is a schematic diagram showing the configuration of the shrink-fitting apparatus 10 according to this embodiment. The shrink-fitting method according to this embodiment is performed using the shrink-fitting apparatus 10. As shown in Figure 2, the shrink-fitting apparatus 10 includes a heating device 11, an adjustment device 12, a measuring device 13, and a control device 14.

[0030] The heating device 11 heats the holder 2. For example, the heating device 11 includes a support column 11a and a coil 11b. The support column 11a supports the coil 11b. For example, the support column 11a is a rod-shaped member extending in the vertical direction. The coil 11b generates heat when an electric current is applied. For example, the coil 11b is a heating element that generates heat according to the principle of high-frequency induction heating. For example, the coil 11b has an annular shape. For example, the central axis of the coil 11b extends in the vertical direction.

[0031] As will be described later, the shrink-fitting method using the shrink-fitting device 10 is performed with the holder 2 set in the heating device 11. Specifically, the holder 2 is inserted through the coil 11b and then set in the heating device 11. In this state, the holder 2 can be heated by generating heat in the coil 11b. When the holder 2 is set in the heating device 11, the relative position between the holder 2 and the coil 11b is maintained at a predetermined position by a support member (not shown).

[0032] The adjustment device 12 adjusts the relative position of the tool 1 inserted into the holder 2 with respect to the holder 2 while the holder 2, which is set in the heating device 11, is heated by the heating device 11. For example, the adjustment device 12 includes a shaft 12a and a drive device 12b. The shaft 12a is a rod-shaped member. The drive device 12b moves the shaft 12a. For example, the drive device 12b is an actuator such as a motor. The drive device 12b may be electric, pneumatic, or hydraulic.

[0033] In the example shown in Figure 2, the shaft 12a is connected to the drive unit 12b and extends upward from the drive unit 12b. Specifically, the drive unit 12b can move the shaft 12a linearly along its central axis. As the shaft 12a moves due to the drive unit 12b, the position of the tip 12a1 of the shaft 12a moves up and down.

[0034] As will be described later, when the holder 2 is heated by the heating device 11, the shaft 12a is inserted through the through hole 2c of the holder 2, and the tip 12a1 of the shaft 12a contacts the rear end 1b of the tool 1. In this state, when the shaft 12a moves, the tool 1 moves integrally with the shaft 12a. In this contact state where the shaft 12a is in contact with the tool 1, the tool 1 can be moved by moving the shaft 12a with the drive device 12b.

[0035] The measuring device 13 measures the relative position of the tool 1, which is inserted into the holder 2 set in the heating device 11, with respect to the holder 2. For example, the measuring device 13 includes a base 13a, a support column 13b, and a measuring probe 13c. The base 13a is installed and fixed on a workbench or the like. The support column 13b extends upward from the base 13a. For example, the support column 13b is a rod-shaped member that extends in the vertical direction. The support column 13b is provided to be movable horizontally relative to the base 13a. The measuring probe 13c is supported by the support column 13b. For example, the measuring probe 13c is a rod-shaped member that protrudes horizontally from the support column 13b. The measuring probe 13c is provided to be movable vertically relative to the support column 13b.

[0036] The measuring device 13 can detect the vertical position of the measuring probe 13c. Here, the vertical reference position of the measuring probe 13c is preset. Therefore, the measuring device 13 can detect the vertical position of the measuring probe 13c with respect to the reference position. The measuring device 13 is also called, for example, a height gauge.

[0037] As will be described later, the measuring device 13 can perform a first measurement to measure the relative position of the tool 1 inserted into the holder 2 with respect to the holder 2 while the holder 2 is heated by the heating device 11.

[0038] The control device 14 includes, for example, a processor 14a and a memory 14b. The processor 14a includes, for example, a central processing unit (CPU). The memory 14b includes, for example, a ROM in which programs are stored and RAM as a work area. The functions of the control device 14 are realized, for example, by the execution of a program stored in the memory 14b by the processor 14a.

[0039] For example, the control device 14 controls the operation of the heating device 11, the adjustment device 12, and the measuring device 13. The control device 14 can also control the operation of devices other than the heating device 11, the adjustment device 12, and the measuring device 13. For example, a shrink-fitting method using the shrink-fitting device 10 can be used in a line operation where the attachment of a tool 1 to a holder 2 is performed sequentially for multiple tools 1. In such a line operation, devices such as a robotic arm are used to transport each component, such as the tool 1 and the holder 2. The control device 14 can also control the operation of the robotic arm, for example.

[0040] The shrink-fitting method using the shrink-fitting apparatus 10 according to this embodiment will be described below with reference to Figures 3 to 6.

[0041] The shrink-fitting method using the shrink-fitting device 10 includes a first step, a second step, a third step, and a fourth step. The first, second, third, and fourth steps are performed in this order. In the line operation described above, the series of steps from the first to the fourth are repeated sequentially for multiple tools 1.

[0042] Figure 3 shows the first step of the shrink-fitting method according to this embodiment. In the first step, the holder 2 is heated by the heating device 11.

[0043] In the first step, the holder 2 is first set in the heating device 11 by a robot arm or the like. As described above, when the holder 2 is set in the heating device 11, the relative position between the holder 2 and the coil 11b is maintained at a predetermined position by a support member (not shown). For example, as shown in Figure 3, the holder 2 is set in the heating device 11 such that the tip 2a of the holder 2 and the upper end 11b1 of the coil 11b of the heating device 11 coincide in the vertical direction. In other words, the area around the tip 2a side of the holder 2 is covered by the coil 11b.

[0044] Then, by generating heat in the coil 11b, the holder 2 is heated. As a result, the holder 2 expands due to the heat, and the inner diameter of the through hole 2c in the holder 2 becomes larger than the outer diameter of the tool 1. With the holder 2 heated in this state, the tool 1 is inserted into the through hole 2c of the holder 2 by a robot arm or the like. Here, the vertical position of the tool 1 is adjusted to a predetermined position by the adjustment device 12. For example, as shown in Figure 3, with the shaft 12a inserted into the through hole 2c of the holder 2 from below, the tool 1 is inserted into the through hole 2c of the holder 2 from above. Then, the rear end 1b of the tool 1 comes into contact with the tip 12a1 of the shaft 12a, thereby positioning the tool 1 in the predetermined position. At this time, the measuring device 13 is retracted to a position where it does not interfere with setting the tool 1 and holder 2 into the heating device 11.

[0045] The position of tool 1 when it is set in the heating device 11 can be set, for example, to a position where the protrusion length L of tool 1 is likely to fall within a specified range, assuming the approximate total length of tool 1. However, since the total length of tool 1 varies from one tool to another, the protrusion length L may not fall within the specified range after the first step alone. Therefore, the second and subsequent steps described later are necessary.

[0046] Figure 4 shows the second step of the shrink-fitting method according to this embodiment. In the second step, while the holder 2 is heated by the heating device 11, a first measurement is performed by the measuring device 13 to measure the relative position of the tool 1 with respect to the holder 2. The relative position of the tool 1 with respect to the holder 2 corresponds to the relative position of the tool 1 and the holder 2.

[0047] In the second step, the holder 2 is kept heated by the coil 11b. Therefore, in the second step, the tool 1 remains movable relative to the holder 2.

[0048] In the second step, first, the support column 13b of the measuring device 13 moves horizontally so that it approaches the coil 11b. At this time, the measuring probe 13c of the measuring device 13 is positioned above the tool 1. Then, the measuring probe 13c of the measuring device 13 descends. After that, the measuring probe 13c stops when it comes into contact with the tip 1a of the tool 1. In this way, the measuring probe 13c descends until it comes into contact with the tip 1a of the tool 1.

[0049] As described above, the measuring device 13 can detect the vertical position of the measuring probe 13c relative to the reference position. In the example in Figure 4, the vertical reference position of the measuring probe 13c is set to the vertical position of the upper end 11b1 of the coil 11b. Then, in the second step, the measuring device 13 detects the vertical position of the measuring probe 13c relative to the reference position when the measuring probe 13c comes into contact with the tip 1a of the tool 1 and stops. As described above, in the vertical direction, the tip 2a of the holder 2 coincides with the upper end 11b1 of the coil 11b of the heating device 11. Therefore, the vertical reference position of the measuring probe 13c coincides with the vertical position of the tip 2a of the holder 2. Thus, in the second step, the protrusion length L of the tool 1 is measured by the measuring device 13 while the holder 2 is heated by the heating device 11. This measurement is called the first measurement. In other words, the result of the first measurement corresponds to the measured value of the relative position of tool 1 with respect to holder 2 in the heated state.

[0050] Figure 5 shows the third step of the shrink-fitting method according to this embodiment. In the third step, while the holder 2 is heated by the heating device 11, the relative position of the tool 1 inserted into the holder 2 with respect to the holder 2 is adjusted by the adjustment device 12.

[0051] In the third step, as in the second step, the holder 2 is kept heated by the coil 11b. Therefore, in the third step, the tool 1 remains movable relative to the holder 2.

[0052] In the third step, first, the amount of adjustment for the vertical position of tool 1 is determined based on the results of the first measurement in the second step. The determination of the amount of adjustment for the vertical position of tool 1 is performed, for example, by the control device 14. For example, the control device 14 obtains the overhang length L (i.e., the current overhang length L) at the time tool 1 is set in holder 2 from the measuring device 13 as a result of the first measurement in the second step. Then, the control device 14 determines the difference between the overhang length L at the time tool 1 is set in holder 2 and the ideal value of the overhang length L as the amount of adjustment for the vertical position of tool 1. The ideal value of the overhang length L is, for example, the median value of the specified range of overhang length L.

[0053] Then, the adjustment device 12 adjusts the vertical position of the tool 1 by a predetermined adjustment amount. In the example in Figure 5, the protrusion length L when the tool 1 is set in the holder 2 is longer than the ideal value of the protrusion length L. Therefore, the adjustment device 12 moves the tool 1 downward by moving the shaft 12a downward. In this way, in the third step, the adjustment device 12 adjusts the relative position of the tool 1 with respect to the holder 2 based on the result of the first measurement by the measuring device 13, while the holder 2 is heated by the heating device 11.

[0054] Furthermore, if the protrusion length L of tool 1 when it is set in holder 2 is shorter than the ideal value of protrusion length L, the adjustment device 12 moves the shaft 12a upward to move tool 1 upward. In this case, the measuring probe 13c of measuring device 13 is retracted upward in advance of the movement of tool 1.

[0055] Furthermore, when moving tool 1, the measuring probe 13c of the measuring device 13 may assist in moving tool 1. For example, when the adjustment device 12 moves tool 1 downward, the measuring probe 13c may descend to push tool 1 downward.

[0056] Figure 6 shows the fourth step of the shrink-fitting method according to this embodiment. In the fourth step, the measuring device 13 performs a second measurement to measure the relative position of the tool 1 with respect to the holder 2 while the holder 2 is in an unheated state, not heated by the heating device 11.

[0057] After the third step, the heating of the coil 11b ends, and the heating of the holder 2 ends. Therefore, in the fourth step, the holder 2 is in an unheated state, not heated by the heating device 11. Consequently, in the fourth step, the tool 1 is in a state where it cannot move relative to the holder 2.

[0058] In the fourth step, first, the measuring probe 13c of the measuring device 13 descends. Then, the measuring probe 13c stops when it comes into contact with the tip 1a of the tool 1. In this way, the measuring probe 13c descends until it comes into contact with the tip 1a of the tool 1. In the fourth step, the measuring device 13 detects the vertical position of the measuring probe 13c relative to the reference position of the measuring probe 13c when the measuring probe 13c comes into contact with the tip 1a of the tool 1 and stops. Therefore, in the fourth step, after the adjustment of the relative position of the tool 1 with respect to the holder 2 by the adjustment device 12 (i.e., after the third step), the protrusion length L of the tool 1 is measured by the measuring device 13 while the holder 2 is in an unheated state, not heated by the heating device 11. This measurement is called the second measurement. In other words, the result of the second measurement corresponds to the measured value of the relative position of the tool 1 with respect to the holder 2 in the unheated state.

[0059] Subsequently, the measuring device 13 retracts to a position where it does not obstruct the removal of the tool 1 and holder 2 from the heating device 11. Specifically, the measuring probe 13c rises and the support column 13b moves horizontally away from the coil 11b. Then, the tool 1 and holder 2 are removed from the heating device 11 by a robot arm or the like and transported to a predetermined location.

[0060] The second measurement in the fourth step is to confirm that the protrusion length L of the tool 1 is within the specified range. If the second measurement shows that the protrusion length L of the tool 1 is not within the specified range, then, for example, the holder 2 may be reheated by the heating device 11 and the vertical position of the tool 1 may be readjusted by the adjustment device 12. Alternatively, if the second measurement shows that the protrusion length L of the tool 1 is not within the specified range, then, for example, the result may be recorded.

[0061] As described above, the shrink-fitting apparatus 10 according to this embodiment includes a heating device 11 for heating a cylindrical holder 2, a measuring device 13 for performing a first measurement to measure the relative position of a tool 1 inserted into the holder 2 with respect to the holder 2 while the holder 2 is heated by the heating device 11, and an adjustment device 12 for adjusting the relative position based on the result of the first measurement by the measuring device 13 while the holder 2 is heated.

[0062] As described above, the shrink-fitting method according to this embodiment includes: a first step of heating a cylindrical holder 2 with a heating device 11; a second step of performing a first measurement with a measuring device 13 to measure the relative position of a tool 1 inserted into the holder 2 with respect to the holder 2 while the holder 2 is heated by the heating device 11; and a third step of adjusting the relative position with an adjustment device 12 based on the result of the first measurement by the measuring device 13 while the holder 2 is heated.

[0063] According to the shrink-fitting device 10 and shrink-fitting method described above, the measurement of the protrusion length L and the adjustment of the relative position described above can be performed in a series of steps at the same location. Therefore, the effort required to move the tool 1 can be reduced, thus shortening the working time. In addition, since the reference for adjusting the position of the tool 1 and the reference for measurement can be matched, the mounting accuracy of the tool 1 can be improved. In other words, it becomes easier to keep the protrusion length L within the specified range. Thus, according to this embodiment, the efficiency of the tool 1 mounting work using shrink-fitting can be improved. Furthermore, according to this embodiment, the tool 1 mounting work using shrink-fitting can be performed at low cost without using expensive equipment such as a tool presetter.

[0064] Furthermore, in the shrink-fitting apparatus 10 and shrink-fitting method according to this embodiment, the measuring device 13 performs a second measurement of the relative position after the adjustment of the relative position by the adjustment device 12, while the holder 2 is in an unheated state and not heated by the heating device 11. This allows confirmation of whether the protrusion length L of the tool 1 is within the specified range. If the second measurement indicates that the protrusion length L of the tool 1 is not within the specified range, the various countermeasures described above can be taken. Note that the second measurement is not necessarily required.

[0065] Furthermore, in the shrink-fitting apparatus 10 and shrink-fitting method according to this embodiment, the adjustment device 12 includes a shaft 12a inserted through the holder 2, and a drive device 12b that moves the tool 1 by moving the shaft 12a while the shaft 12a is in contact with the tool 1. This appropriately adjusts the relative position of the tool 1 inserted through the holder 2 with respect to the holder 2. In addition, the tool 1 can be easily removed from the holder 2 by continuously moving the shaft 12a upward while the shaft 12a is in contact with the tool 1. Note that the adjustment device 12 only needs to have the function of adjusting the relative position of the tool 1 with respect to the holder 2, and is not limited to the above example.

[0066] The above describes an example in which the holder 2 is fixed and the adjustment device 12 moves the tool 1. However, the tool 1 may be fixed and the adjustment device 12 moves the holder 2.

[0067] Furthermore, the above description illustrates an example in which the vertical reference position of the measuring probe 13c is set to the vertical position of the upper end 11b1 of the coil 11b. However, the reference position is not limited to the above example. If the tip 2a of the holder 2 and the upper end 11b1 of the coil 11b of the heating device 11 do not coincide in the vertical direction, it is preferable to set the reference position in the vertical direction of the tip 2a of the holder 2. This allows for easy measurement of the protrusion length L.

[0068] Furthermore, the above description illustrates an example where the measuring device 13 is a contact-type device. However, the measuring device 13 may also be a projection-type device.

[0069] The following describes various modified examples with reference to Figures 7 to 10.

[0070] Figure 7 is a schematic diagram showing the configuration of a shrink-fitting device 10A according to the first modified example of this disclosure. As shown in Figure 7, the shrink-fitting device 10A according to the first modified example differs from the shrink-fitting device 10 described above in that a first detection device 12c is added to the adjustment device 12.

[0071] The first detection device 12c detects the contact state in which the shaft 12a is in contact with the tool 1. For example, the first detection device 12c is a touch sensor provided on the tip 12a1 of the shaft 12a. The first detection device 12c can detect whether or not the rear end 1b of the tool 1 is in contact with the tip 12a1 of the shaft 12a. For example, the detection result of the first detection device 12c is output to the control device 14. For example, if the control device 14 detects that the shaft 12a is not in contact with the tool 1 in the first, second, or third step described above, it will stop the shrink-fitting operation in which the tool 1 is attached to the holder 2 because it will be difficult to proceed with the shrink-fitting operation in a sound manner.

[0072] As described above, in the shrink-fitting apparatus 10A and shrink-fitting method according to the first modified example, the adjustment device 12 includes a first detection device 12c that detects the contact state in which the shaft 12a is in contact with the tool 1. This makes it possible to stop the shrink-fitting operation when the shaft 12a is not in contact with the tool 1 and it is difficult to carry out the shrink-fitting operation of attaching the tool 1 to the holder 2 in a sound manner.

[0073] The above example describes an instance where the first detection device 12c is a touch sensor. However, the first detection device 12c is not limited to the above example and only needs to have the function of detecting a contact state in which the shaft 12a is in contact with the tool 1. For example, the first detection device 12c may be a force sensor that detects the force acting on the shaft 12a. In this case, the contact state may be detected by whether the force detected by the force sensor is sufficiently large. The force sensor may be provided on the shaft 12a of the adjustment device 12, or on the drive device 12b. Also, for example, the first detection device 12c may be a load sensor that detects the load (e.g., torque) of the drive device 12b of the adjustment device 12. In this case, the contact state may be detected by whether the load detected by the load sensor is sufficiently large.

[0074] Figure 8 is a schematic diagram showing the configuration of a shrink-fitting device 10B according to a second modified example of the present disclosure. As shown in Figure 8, the shrink-fitting device 10B according to the second modified example differs from the shrink-fitting device 10 described above in that a second detection device 15 is added.

[0075] The second detection device 15 detects information about the tool 1 other than its relative position to the holder 2. Examples of such information include information indicating whether or not there are chips in the cutting edge of the tool 1, or information indicating the misalignment of the tool 1 with respect to the holder 2. The misalignment of the tool 1 with respect to the holder 2 refers to the misalignment of the central axis of the tool 1 with respect to the central axis of the holder 2 (for example, the inclination angle between the two central axes, or the distance between the two central axes at the tip 2a of the holder 2).

[0076] The second detection device 15 may be, for example, a projection-type device such as a tool presetter. In this case, the second detection device 15 can detect the detailed shape and orientation of the tool 1 by, for example, shining light onto the tool 1 and capturing the resulting shadow with a camera. As a result, the second detection device 15 can detect information indicating whether or not there is a chip in the cutting edge of the tool 1, or information indicating misalignment of the tool 1 with respect to the holder 2. The detection of such information by the second detection device 15 may be performed, for example, in the fourth step described above.

[0077] As described above, in the shrink-fitting apparatus 10B and shrink-fitting method according to the second modified example, the shrink-fitting apparatus 10B is equipped with a second detection device 15 that detects information about the tool 1 other than the relative position of the tool 1 with respect to the holder 2. This makes it possible to obtain more information about the tool 1. Therefore, for example, defects in the tool 1 itself or defects in the mounting posture of the tool 1 to the holder 2 can be identified.

[0078] In addition, in the shrink-fitting device 10B according to the second modified example, a first detection device 12c may be added to the adjustment device 12, similar to the shrink-fitting device 10A according to the first modified example described above.

[0079] Next, with reference to Figures 9 and 10, a shrink-fitting apparatus 10C according to a third modified example of the present disclosure, and a shrink-fitting method using the shrink-fitting apparatus 10C will be described.

[0080] The shrink-fitting apparatus 10C according to the third modified example includes a heating device 11, an adjustment device 12, a measuring device 13, and a control device 14, similar to the shrink-fitting apparatus 10 described above. However, the shrink-fitting apparatus 10C according to the third modified example differs in the procedure of the shrink-fitting method compared to the shrink-fitting apparatus 10 described above.

[0081] The shrink-fitting method using the shrink-fitting device 10C includes a first step, a second step, and a third step. The first, second, and third steps are performed in this order. In the line operation described above, the series of steps from the first to the third are repeated sequentially for multiple tools 1.

[0082] Figure 9 shows the first step of a shrink-fitting method using a shrink-fitting device 10C according to a third modified example of the present disclosure. In the first step, a third measurement, in which the total length FL of the tool 1 is measured, is performed by the measuring device 13.

[0083] In the first step, the tool 1 is first set into the jig 16 by a robot arm or the like. In the example in Figure 9, the tool 1 is set into the jig 16 so that its rear end 1b is attached to the upper surface 16a of the jig 16. The tool 1 is also set into the jig 16 in a position that extends in the vertical direction. Note that in Figure 9, the shape of the jig 16 is shown simply for the sake of understanding, but the shape of the jig 16 is not particularly limited.

[0084] Then, after the tool 1 is set into the jig 16, the support column 13b of the measuring device 13 moves horizontally so that it approaches the jig 16. At this time, the measuring probe 13c of the measuring device 13 is positioned above the tool 1. Then, the measuring probe 13c of the measuring device 13 descends. After that, the measuring probe 13c stops when it comes into contact with the tip 1a of the tool 1. In this way, the measuring probe 13c descends until it comes into contact with the tip 1a of the tool 1.

[0085] As described above, the measuring device 13 can detect the vertical position of the measuring probe 13c relative to the reference position. In the example in Figure 9, the vertical reference position of the measuring probe 13c is set to the vertical position of the upper surface 16a of the jig 16. In the first step, the measuring device 13 detects the vertical position of the measuring probe 13c relative to the reference position when the measuring probe 13c comes into contact with the tip 1a of the tool 1 and stops. Therefore, in the first step, the total length FL of the tool 1 (i.e., the length from the tip 1a to the rear end 1b of the tool 1) is measured by the measuring device 13. This measurement is called the third measurement. In other words, the result of the third measurement corresponds to the measured value of the total length FL of the tool 1.

[0086] Figure 10 shows the second and third steps using the shrink-fitting apparatus 10C of the shrink-fitting method according to the third modified example of the present disclosure. In the second step, the holder 2 is heated by the heating device 11. In the third step, while the holder 2 is heated by the heating device 11, the relative position of the tool 1 inserted into the holder 2 with respect to the holder 2 is adjusted by the adjustment device 12.

[0087] In this third modification, the holder 2 is set in the heating device 11 by a robot arm or the like before the holder 2 is heated by the heating device 11. As described above, when the holder 2 is set in the heating device 11, the relative position between the holder 2 and the coil 11b is maintained at a predetermined position by a support member (not shown). Also, with the holder 2 set in the heating device 11, the shaft 12a of the adjustment device 12 is inserted through the through hole 2c of the holder 2 from below. In this state, the shaft 12a moves to a target position determined based on the results of the third measurement in the first step.

[0088] The target position of the shaft 12a is determined, for example, by the control device 14. For example, the control device 14 obtains the total length FL of the tool 1 from the measuring device 13 as a result of the third measurement in the first process. Then, the control device 14 determines the target position of the shaft 12a based on the total length FL of the tool 1, so that the overhang length L is an ideal value when the tool 1 is set in the holder 2 in a later process and the rear end 1b of the tool 1 contacts the tip 12a1 of the shaft 12a. The ideal value of the overhang length L is, for example, the median value of a specified range of overhang lengths L.

[0089] In the second step, as described above, the holder 2 is set in the heating device 11 and the shaft 12a has moved to the target position, and the holder 2 is heated by generating heat in the coil 11b. As a result, the holder 2 expands due to the heat, and the inner diameter of the through hole 2c in the holder 2 becomes larger than the outer diameter of the tool 1.

[0090] In the third step, with the holder 2 heated in this manner, the tool 1 is inserted into the through-hole 2c of the holder 2 by a robot arm or the like. Specifically, as shown in Figure 10, with the shaft 12a inserted into the through-hole 2c of the holder 2 from below, the tool 1 is inserted into the through-hole 2c of the holder 2 from above. The tool 1 is then positioned when the rear end 1b of the tool 1 comes into contact with the tip 12a1 of the shaft 12a. Here, as described above, the position of the shaft 12a is a target position determined based on the results of the third measurement in the first step. The tool 1 is then positioned by such a shaft 12a. In other words, in the third step, with the holder 2 heated by the heating device 11, the adjustment device 12 adjusts the relative position of the tool 1 with respect to the holder 2 based on the results of the third measurement by the measuring device 13.

[0091] As described above, the shrink-fitting apparatus 10C according to the third modified example comprises a measuring device 13 that performs a third measurement to measure the total length FL of the tool 1, a heating device 11 that heats the cylindrical holder 2, and an adjustment device 12 that adjusts the relative position of the tool 1 inserted into the holder 2 with respect to the holder 2 based on the result of the third measurement by the measuring device 13 while the holder 2 is heated by the heating device 11.

[0092] As described above, the shrink-fitting method according to the third modified example includes a first step of performing a third measurement to measure the total length FL of the tool 1 using a measuring device 13, a second step of heating the cylindrical holder 2 with a heating device 11, and a third step of adjusting the relative position of the tool 1 inserted into the holder 2 with respect to the holder 2 using an adjustment device 12, based on the result of the third measurement by the measuring device 13 while the holder 2 is heated by the heating device 11.

[0093] According to the shrink-fitting device 10C and shrink-fitting method described above, the protrusion length L can be adjusted based on the total length FL of the tool 1, which has been measured in advance, rather than setting the tool 1 into the holder 2. Therefore, the working time while the holder 2 is heated by the heating device 11 can be shortened, and thus the time required for heating and cooling of the tool 1 and holder 2 can be shortened. Thus, the efficiency of the tool 1 installation work using shrink-fitting can be improved.

[0094] In particular, in the above example, the shaft 12a moves to a target position determined based on the results of the third measurement in the first step before the holder 2 is heated by the heating device 11. Then, with the shaft 12a moved to the target position, the holder 2 is heated by the heating device 11 and the tool 1 is set into the holder 2. Therefore, compared to, for example, the case where the shaft 12a moves after the holder 2 has been heated by the heating device 11 and the tool 1 has been set into the holder 2, the time during which the holder 2 is heated by the heating device 11 can be shortened. Furthermore, this also helps to suppress the reduction in the clearance between the through hole 2c of the holder 2 and the tool 1 due to thermal expansion of the tool 1, which would otherwise hinder the relative movement of the tool 1 with respect to the holder 2. However, the tool 1 may be set into the holder 2 while the holder 2 is heated by the heating device 11, and then the shaft 12a may move to the target position. In other words, the holder 2 may be heated by the heating device 11, and the tool 1 may be set in the holder 2 before the shaft 12a is moved.

[0095] While embodiments of this disclosure have been described above with reference to the attached drawings, it goes without saying that this disclosure is not limited to such embodiments. It will be obvious to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally also fall within the technical scope of this disclosure. [Explanation of symbols]

[0096] 1 tool 2 holders 10 Shrink-fitting device 10A Shrink-fitting device 10B Shrink-fitting device 10C shrink-fitting device 11 Heating device 12 Adjustment device 12a shaft 12b Drive unit 12c First detection device 13 Measuring devices 15. Second detection device

Claims

1. A heating device for heating a cylindrical holder, A measuring device that performs a first measurement to measure the relative position of a tool inserted into the holder with respect to the holder while the holder is heated by the heating device, In the heated state, an adjustment device adjusts the relative position based on the result of the first measurement by the measuring device, Equipped with, Shrink-fitting device.

2. The measuring device performs a second measurement of the relative position after the adjustment of the relative position by the adjustment device, while the holder is in an unheated state and not heated by the heating device. The shrink-fitting apparatus according to claim 1.

3. The adjustment device is, A shaft inserted into the holder, A drive device that moves the tool by moving the shaft while the shaft is in contact with the tool, including, The shrink-fitting apparatus according to claim 1.

4. The adjustment device includes a first detection device for detecting the contact state. The shrink-fitting apparatus according to claim 3.

5. The system includes a second detection device for detecting information about the tool other than the relative position, The shrink-fitting apparatus according to any one of claims 1 to 4.

6. The first step involves heating a cylindrical holder with a heating device, A second step involves performing a first measurement using a measuring device to measure the relative position of a tool inserted into the holder with respect to the holder while the holder is heated by the heating device, In the heated state, a third step is to adjust the relative position using the adjustment device based on the result of the first measurement by the measuring device, including, Shrink-fitting method.

7. A measuring device that performs a third measurement to measure the total length of the tool, A heating device for heating a cylindrical holder, An adjustment device that adjusts the relative position of the tool inserted into the holder with respect to the holder, based on the result of the third measurement by the measuring device, while the holder is heated by the heating device, Equipped with, Shrink-fitting device.

8. The first step involves performing a third measurement, measuring the total length of the tool, using a measuring device. A second step involves heating a cylindrical holder with a heating device, A third step in which, while the holder is heated by the heating device, the relative position of the tool inserted into the holder with respect to the holder is adjusted by the adjustment device based on the result of the third measurement by the measuring device, including, Shrink-fitting method.

Images