JPH0438247Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention is a standard for aligning a reference surface such as a machining table surface of various machine tools with the tip of a tool or the machining center on the same plane. It is applied to the position detection device, especially when the probe arm of the detection device is
This invention relates to a reference position detection device that is movable in three axes in the Y and Z directions.

[Conventional technology]

Generally, when machining a workpiece with various machine tools, the machining table surface serves as one machining reference surface.
For this purpose, before starting the machining of the workpiece, for example in a milling machine, a shaver, etc., the cutting edge of the tool is positioned on the same plane as the surface of the machining table. It is necessary to use this position as a machining reference in the vertical direction (Z-axis direction) of the tool. In this way, the distance from the processing table surface to the cutting edge of the tool can be accurately known, so even if the thickness of the workpiece varies, it can be easily finished in a constant manner. Similarly, in the case of a boring machine, if the center of rotation of the cutting tool and the position of the machining table can be accurately known, machining work becomes easier.

Conventionally, when using the machining table surface as a measurement reference for a tool, the tool should be brought into direct contact with the machining table surface, but since this may damage the machining table surface or the tool, Figure 3 a and b This was done using the method shown below.

This shows an example of a slicing machine. In the figure, 1 is a processing table of a machine tool. A workpiece is placed and fixed on the processing table surface 1a on the upper surface of this processing table 1, and processed into a predetermined size. It is something. The processing table 1 is configured to be slidable in the front-rear direction (X-axis direction) by a guide mechanism (not shown). Reference numeral 2 denotes a saddle that moves in the left and right lateral directions (Y-axis direction) along the cross rail 4, and also moves the main shaft portion 5 to which the tool 5a is attached by a chuck or the like in the vertical direction (Z-axis direction). It is something that makes you A scale 6a is attached to the main shaft portion 5, and together with a head portion 6b fixed to the saddle 2, the scale portion 6 is configured. The scale section 6 measures the amount of relative movement of the main shaft section 5 with respect to the saddle 2, and a signal is outputted from the scale section 6 to the counter device main body 8 via a cable 10, so that the amount of movement of the main shaft section 5 is displayed. Further, on the processing table 1, a dial gauge 3 is installed at a measuring section 3.
A is fixed in a state where it projects above the processing table surface 1a. The displacement amount of the measuring tip 3a is outputted from the dial gauge 3 through a cable 10 and displayed on the counter device main body 9.

Further, in order to position the processing table surface 1a and the cutting edge of the bide 5a on the same plane, a detection plate 7 having a highly accurate finished surface 7a is used. As shown in FIG. 3a, first, the detection plate 7 is placed on the processing table surface 1a so as to straddle the measuring head 3a of the dial gauge 3 from above, with the finished surface 7a as the lower surface. At this time, the measuring element 3a is pushed down by the detection plate 7, and the upper end of the measuring element 3a and the processing table surface 1a become on the same plane. Then, in this state, the display section of the counter device main body 9 is reset to zero, for example. Next, the detection plate 7 is removed and the probe 3a of the dial gauge 3 is returned to its original position. Further, the saddle 2 and the processing table 1 are moved so that the tip of the cutting tool 5a and the measuring tip 3a are aligned on the same axis. Then, the main shaft portion 5 is lowered, and the tip of the cutting tool 5a is brought into contact with the probe 3a of the dial gauge 3. When the main shaft portion 5 is further lowered, the probe 3a is also lowered, and accordingly, the value on the display section of the counter device main body 9 gradually approaches zero and finally reaches zero. At this time, the tip of the cutting tool 5a is located on the same plane as the processing table surface 1a.
By resetting the display section of the counter device main body 8 to zero (a reference value may also be input), the distance between the processing table surface 1a and the tip of the cutting tool 5a can be known at all times.

As described above, the processing table surface 1a and the cutting tool 5
If the positional relationship of a is known, even if the shape of the workpiece is different, it is possible to accurately process the workpiece into the desired dimensions using the processing table surface 1a as a processing reference.

[The problem that the invention is trying to solve]

However, when aligning the tip of the tool with the machining table as described above, it is necessary to align the dial gauge and then align the tool, which requires double effort, and the need to replace the tool. If this occurs frequently, there is a problem in that work efficiency is significantly reduced. Further, the dial gauge is movable in the vertical direction (Z-axis direction) of the measuring stylus 3a, but cannot be moved in the front and rear and left and right directions (X-axis and Y-axis directions). Therefore, there is no escape from the forces in the X and Y axis directions, which may cause damage to the tool or dial gauge when aligning the tool.

[Means for solving problems]

The present invention was devised in view of the above-mentioned problems, and aims to provide a reference position detection device that can align the processing table and the tip of the tool with an extremely simple configuration. The detection device main body includes a case that forms an outer frame of the detection device main body and whose bottom surface is placed on a reference surface, at least three fixed side electrodes disposed inside the case, and a case that faces the bottom surface. It has a cylindrical body having an opening axis, a tip part parallel to the bottom surface of the case and regulated at a constant height with respect to the bottom surface, and a spherical hinge ball that fits into the inner peripheral surface of the cylindrical body, A probe arm that is movable in the X, Y, and Z three-axis directions in response to external force, a movable electrode formed at the other end of the probe arm, and a movable electrode such that the movable electrode comes into contact with the fixed electrode after the external force is removed. an elastic member that returns and holds the probe arm in a predetermined position; and an elastic member that penetrates the case;
The tip part is composed of a plurality of screws that press the outer periphery of the cylindrical body, and an output part that senses the slight movement of the probe arm by the separation between the movable electrode and the fixed electrode and generates a predetermined signal. This is a characteristic feature.

[Effect]

Since the reference position detecting device of the present invention has the above-described configuration, for example, the main body of the detecting device is placed on the processing table of a machine tool, a tool is lowered from above, and the tip of the tool is placed at the tip of the probe arm. It has the effect of sensing the contact between the two by transmitting a predetermined signal at the same time when the two touch. Further, at the same time as the contact, the probe arm descends downward, forming a so-called relief.

〔Example〕

The reference position detection device of the present invention will be explained in detail below with reference to the drawings. FIG. 1a is a vertical sectional view showing an embodiment of the reference position detection device, and FIG.
The sectional view taken along the line I--I in FIG. 2 is a diagram showing an example of the use of the present invention.

This reference position detection device is composed of a detection device main body, a counter device main body, etc. that receives signals from the detection device main body. And Figure 1a,
As shown in FIG. 1B, 20 is a main body of the detection device, which is made up of a case portion A forming an outer wall, and various members including a probe arm, electrodes, and the like.

Case part A includes an upper case 21 and a lower case 2.
2 and a cap 23, and the cap 23 includes a dustproof seal member 37 made of a flexible material.
a also has a seal member 37 on the upper case 21.
b is attached. Reference numeral 24 designates a probe arm whose tip 24a is parallel to the bottom surface 22a of the case, and a hinge ball 25 made of stainless steel or bearing steel is provided in the middle. The end portion is screwed onto the movable electrode 26. Further, 27 is an electrode holder made of an insulating material, and is held between the upper case 21 and the lower case 22 via an O-ring 31.
Three fixed side electrodes 29 are arranged on this electrode holder 27, and support a movable side electrode 26 which is biased upward by an elastic member 30, which will be described later, from above. 24 is defined at a fixed position. At this time, it is desirable that the movable side electrode 26 be disposed parallel to the case bottom surface 22a.
The movable electrode 26, the fixed electrode 29, and a substrate 28, which will be described later, constitute an output section.

Furthermore, the movable side electrode 26 and each fixed side electrode 2
9 forms a contact mechanism. Reference numeral 28 denotes a substrate having a detection circuit, which is fixed to the fixed side electrode 29 with a nut 32 via a holder 29'. Moreover, between the substrate 28 and the movable electrode 26,
An elastic member 30 such as a spring is stretched at a position facing the fixed side electrode 29, and serves as a so-called return mechanism for the movable side electrode 26 and the probe arm 24.
This is to effectively return and reproduce the original position.

A cylindrical body 33 has an inner circumferential surface that contacts the hinge ball 25 and supports the rolling movement of the hinge ball 25. The sleeve 34 is fixed to the upper and lower cases 21 while holding the upper and lower surfaces of the cylindrical body 33. This cylindrical body 33 is the hinge ball 2
Similarly to No. 5, it is made of bearing steel, stainless steel, tool steel, etc., which are highly wear resistant and have extremely little change in shape due to external forces.

In this case, there must be no gap between the cylindrical body 33 and the hinge ball 25 in order to ensure reproducibility of returning the probe arm 24 to its normal position. However, in order to make assembly work easier,
During assembly, there is a small gap between the two, generally several μm or more.
A gap of approximately several tens of μm is provided as a gap. Then, a plurality of screws 36 are passed through the upper case 21, thereby pressing and deforming the outer circumferential surface of the cylindrical body 33, thereby eliminating the gap between the inner circumferential surface of the cylindrical body 33 and the hinge ball 25.

If an object to be measured such as a tool comes into contact with the tip 24a of the probe arm 24 and at least one of the fixed side electrodes 29 separates from the movable side electrode 26, the detection circuit formed on the substrate 28 A contact detection signal is transmitted from the connector 35, and the signal is output to the outside through the connector 35.

The measurement accuracy of this detection device main body 20 is determined by
Since it is determined by the parallelism of a, even including assembly accuracy, it is desirable that the error in parallelism is 10 μm or less at the end of the tip portion 24a.

Next, FIG. 2 shows an example of measurement using the reference position detection device of the present invention.

In the figure, the same parts as those of the conventional one shown in FIGS. 3a and 3b are given the same reference numerals and explained.

First, the total height from the case bottom 22a of the detection device main body 20 to the tip 24a of the probe arm 24 is accurately measured in advance and input into the counter device main body 8'.
0 is placed on the processing table surface 1a, the processing table 1 and the saddle 2 are moved, and the cutting tool 5a fixed to the main shaft portion 5 is moved onto the probe arm 24. Then, the main shaft 5 is gradually lowered. The amount of movement of the main shaft portion 5 is measured by the scale portion 6, and the amount of movement is displayed on the counter device main body 8'. The main shaft portion 5 is further lowered, and the tip of the cutting tool 5a comes into contact with the tip 24a of the probe arm 24. Then, a contact detection signal is output from the detection device main body 20 to the counter device main body 8'. In this state, on the counter device main body 8', the movement amount of the main shaft section 5 that was previously displayed is canceled, and the total height of the detection device main body 20 stored in advance is newly displayed as the movement amount of the main shaft section 5. The alignment between the processing table surface 1a and the cutting tool 5a is completed.

Further, even if the cutting tool 5a further descends after contacting the tip 24a, the contact point arm 24 will not
Since relief is provided in the vertical axis direction (Z-axis direction), the cutting tool 5a or the probe arm 24 will not be damaged. Furthermore, even if the cutting tool 5a is accidentally brought into contact with the probe arm 24 from the front and rear or the left and right directions, the tool 5a or the probe arm 24 will not be damaged because the probe arm 24 has clearances in the front, rear, left and right directions. There isn't.

〔effect〕

In the reference position detecting device of the present invention, the main body of the detecting device can be freely placed at any position on the processing table, so that quick settings can be made. In addition, the gauge head arm can move freely in the X, Y, and Z3 axes directions, and the escape distance of the gauge head arm is large, so if a tool comes into contact with the gauge head arm, the tool or the gauge head arm will not be damaged. do not have. Furthermore, X, Y
Even if a tool hits the measuring arm from the axial direction, neither will be damaged. This is particularly effective for large machines with large moving parts that have large inertia. Furthermore, since the counter device main body of the reference position detection device also serves as the counter device main body in the Z-axis direction of the machine tool, the system itself is simplified. Furthermore, alignment of the tool and machining table only needs to be done once, which simplifies the measurement process compared to conventional methods that required double measurements.
Moreover, it has excellent effects such as greatly improved operability. Further, after the measuring head arm is inserted into the cylindrical body, the outer periphery of the cylindrical body is pressed by a screw, the cylindrical body is deformed, and the inner periphery of the cylindrical body is brought into contact with the hinge ball. Therefore, it is possible to easily assemble the detection device main body, and the return reproducibility can be maintained favorably.

The present invention is not limited to the embodiments described above, and can be modified in various ways, such as when the processing reference surface is other than the processing table, for example, the upper surface of the workpiece is the processing reference surface.

Furthermore, in some cases, if an adsorption device such as a magnet is provided within a range that does not impair operability, it is possible to prevent the detection device main body from shifting.

[Brief explanation of drawings]

FIG. 1a is a longitudinal sectional view showing an embodiment of the present invention, FIG. 1b is a sectional view taken along the line II in FIG. 1a,
FIG. 2 is a diagram showing an example of measurement by the reference position detecting device of the present invention, and FIGS. 3a and 3b are diagrams showing conventional alignment of the processing table surface and the tool. 20...Detection device main body, A...Case, 24...
...Sensor arm, 24a... Tip, 25... Hinge ball, 26... Movable side electrode, 27... Electrode holder, 28... Substrate, 29... Fixed side electrode,
30...Elastic member, 33...Cylindrical body, 36...Screw.

Claims (1)

[Scope of utility model registration request] In a reference position detection device that includes a detection device body and a counter device body that receives signals output from the detection device body, and measures the positional relationship between a reference surface such as a machining table of various machine tools and a tool, the detection device The main body includes a case that forms an outer frame of the detection device main body and whose bottom surface is placed on a reference surface, at least three fixed side electrodes disposed inside the case, and an opening axis toward the bottom surface. A cylindrical body,
It has a tip that is parallel to the bottom surface of the case and is regulated at a constant height with respect to the bottom surface, and a spherical hinge ball that fits into the inner circumferential surface of the cylindrical body, and that A probe arm that is movable in the Z3 axis direction, a movable electrode formed at the other end of the probe arm, and a probe arm that is placed in a predetermined position so that the movable electrode contacts the fixed electrode after the external force is removed. an elastic member for returning and holding; penetrating the case;
The tip part is composed of a plurality of screws that press the outer periphery of the cylindrical body, and an output part that senses the slight movement of the probe arm by the separation between the movable electrode and the fixed electrode and generates a predetermined signal. Characteristic reference position detection device.