JPS5940101A - Balancing device of measuring instrument - Google Patents

Abstract

PURPOSE:To reduce the size and weight of a titled measuring instrument by balancing the weight of a shaft material, etc., fitted with a measuring element by the pressure in a cylinder. CONSTITUTION:The lower end of a probe shaft 6 is held by a hand and the measuring element 5 is moved in three dimensions to abut on bodies to be measured successively for measurement. When the shaft material 13 is elevated while the air pressure balancing with the gross weight of a movable part is supplied into the cylinder 19, the capacity in the cylinder 19 increases to cause a decrease in the internal pressure and then the primary-side pressure of a regulator 35 drops below set pressure to lower the air pressure at the air outlet of the regulator 34, thereby closing a nozzle 51 by the compressive force of a set spring 53. Then, a diaphragm 47 is pressed down because of a rise in back pressure to operate a main valve 42 in the opening direction, holding the secondary side at the set pressure. When the shaft material 13 is lowered, the main valve 42 is operated in the closing direction and excessive air is discharged out through a relief hole 60. Thus, the weight of the movable member is balanced, so the probe shaft 6 is moved up and down during measurement by relatively small force.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a measuring instrument, and more particularly to a balance device that reduces the operating force of a probe.

For example, in a coordinate measuring machine, a horizontal beam is moved in the front-rear direction (Y-axis direction) of the surface plate via supports on both sides of the surface plate, and a slider is moved along the horizontal beam in the left-right direction (X-axis direction) of the surface plate. ) to the slider? Rose shafts are provided to be movable in the vertical direction (z-axis direction) of the surface plate, and by moving these in the x-, y-, and z-axis directions, the probe attached to the lower end of the probe shaft is sequentially attached to the object to be measured. The device is moved in a three-dimensional direction while in contact with the object to measure the dimensions, shape, etc. of the object. With such a structure, the weight of the probe shaft poses a major operational obstacle when moving the probe shaft while grasping the lower end during measurement.

Therefore, in conventional measuring machines, one end of a wire is connected to the upper end of the prong shaft, the other end of this wire is connected to a weight through a pulley, and the weights of this weight and the prong shaft are balanced against each other. It used a counterweight method. However, with this counterweight method, in addition to the weight of the weight that balances the weight of the prologue shaft, the weight of the pulley and cover is added to the horizontal beam via the slider, which causes deflection of the horizontal beam, which adversely affects measurement accuracy. This was a contributing factor to the Therefore, as a countermeasure to this point, increasing the size of the structure can prevent a decrease in accuracy, but on the other hand, high-speed measurement cannot be expected due to the increase in the weight of each member.

On the other hand, in order to solve the drawbacks of the counterweight method mentioned above, the prologue shaft and the air cylinder are connected to each other via a rope or a link, and the weight of the prologue shaft is balanced by the air pressure of the air cylinder. An air cylinder method was developed.

However, even in this method, since the cylinder is provided separately from the prong shaft, the overall size is increased, and as a result, the weight of the cover, mounting member, etc. is not considered.

An object of the present invention is to provide a lance device for a measuring machine that can solve the drawbacks of both types and can be made smaller and lighter.

Therefore, in the present invention, a hollow thin member with a measuring element attached to the lower end is provided in the structure so as to be movable in the vertical direction, and a cylinder device consisting of a cylinder, a piston, and a piston rod is fitted inside this shaft member. The upper end of the piston rod is supported by the structure, and the pressure fluctuation inside the cylinder due to the vertical movement of the cylinder is kept within a certain pressure. In other words, by providing a cylinder device that controls the weight of the shaft material by the pressure inside the cylinder inside the shaft material to which the gauge head is attached, the overall size and weight can be reduced. The aim is to achieve the above objectives.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 shows the external appearance of the three-dimensional measuring machine of this embodiment.

The three-dimensional measuring machine has support columns 2A installed on both sides of the surface plate 10.
, 2B, the horizontal beam 3 is directed in the front-rear direction of the surface plate 1 (
The slider 4 moves along the horizontal beam 3 in the left-right direction (X-axis direction) of the surface plate 1.
A probe shaft 6 having a measuring element 5 at its lower end is provided so as to be movable in the vertical direction (z-axis direction) of the surface plate 1. In other words, the measuring element 5 can be moved in three-dimensional directions through these structures. Furthermore, when the measuring head 5 is moved in three-dimensional direction and comes into contact with the object to be measured placed on the surface plate 1, the position of the horizontal beam 3 in the Y-axis direction, the slider 4 in the X-axis direction and the position of the probe shaft 6 in the two-axis directions are each detected by a detector (not shown) and then displayed on a display or the like.

FIG. 2 shows the internal structure of the prong shaft 6. In the probe shaft 6, a prismatic shaft member 13 having a circular hollow hole 12 extending toward the central axis is attached to a holding frame 11 that is integrally formed at the top and bottom positions of the front surface of the slider 4, and is movable up and down. It is held so that it can move freely in any direction. As shown in FIG. 3, there is a shaft 1 between the shaft 13 and the holding frame 11.
Air pads 14 that eject compressed air to the four outer surfaces of the housing 3 are each held via bolts 15.

Further, the shaft member 13 is provided with a holder 16 at its lower end to allow the measuring element 5 to be taken out.
A cylinder device 17 is fitted into the hollow hole 12 .

The cylinder device 17 includes a cylinder 19 that is fitted into the hollow hole 12 of the shaft member 13 and integrally connected to the shaft member 13 via a connecting plate 18, and a cylinder 19 that is slidable inside the cylinder 19. The fitted piston 21 and the cylinder 1
9, and a cylinder head 20 that passes through the center of the cylinder head 20 and has a lower end that is connected to the piston 21.
The piston rod 22 is connected to the piston rod 22.

The upper end of the piston rod 22 projects upward through an insertion hole 24 of a bracket 23 fixed to the slider 4. At the end of the piston rod 22 that protrudes upward from the bracket 23, there is a flange plate 26 supported on the upper surface of the bracket 23 via a bearing 25, which is attached to a nut 27.
Fixed by That is, the upper end of the piston rod 22 is supported by the bracket 23 so as to be movable in the radial direction of the cylinder 19. Further, an air supply hole 28 is formed in the cylinder head 20, and a pressure regulating device 30 that maintains the pressure of the cylinder device 17 at a constant pressure is connected to the air supply hole 28 via a pipe 29.

As shown in FIG. 4, the pressure regulating device 30 is configured such that air at a constant pressure, for example, 5 kq/d, supplied from a pressure source 31 is supplied to an air filter 32 and a micro mist separator 3.
3 to the first regulator 34.

The first regulator 34 has a secondary side connected to the air pad 1.
4 and the second regulator 35, respectively,
The pressure on the secondary side is maintained at a set pressure, for example, 4 ky/ca. The second railulator 35, like the secondary tank 31, maintains the pressure on the secondary side, that is, the pressure inside the cylinder 19, at a set pressure, for example, 1.7 $/cyl.

Incidentally, the functions of the first regulator 34 and the second regulator 35 will be briefly explained with reference to FIG. 5. Now, when the setting screw 41 is completely loosened, the main pulp 42 is closed, so the air supply port 4
The air pressure supplied to No. 3 does not flow to the exhaust port 44, but a part of it flows from the flow path 45 through the fixed throttle 46 to the upper chamber 48 partitioned by the first diaphragm 41, and becomes the nozzle back pressure. , 7, since the wrapper 5o is open, the water is discharged from the nozzle 51 through the flow path 52 to the atmosphere.

Here, rotate the setting screw 41 and set the setting spring 53.
When compressed, the compression force of the setting spring 53 causes the second diaphragm 54 and the third diaphragm 55 to
The seven wrapper 50 closes the nozzle 51 via. Then,
As the Guzur back pressure increases and the first diaphragm 47 is pushed down, the main pulp 42 is opened via the pulp blonde 56, and as a result, the air pressure supplied to the air supply port 43 flows to the exhaust port 44. . The air pressure flowing to the exhaust port 44 passes through the flow path 57 to the first diaphragm 4.
It flows into the lower chamber 49 partitioned by a T, and flows into the upper chamber 48.
The second diaphragm 54' and the third tire flamm 5 are further discharged from the flow path 58.
5 flows into a feedback chamber 59 partitioned by 5 and is balanced with the compression force of the setting spring 53.

In this state, if the air pressure in the exhaust port 44 increases too much, the second diaphragm 54 is pushed up as the pressure in the feedback chamber 59 increases, and as a result the flapper 50 rises and the nozzle 51 is opened. Then, the nozzle back pressure decreases, so the first diaphragm 4γ is pushed up, and as a result, the main pulp 42 closes and the escape hole 60 closes.
is opened and excess air is released into the atmosphere. Conversely, when the air pressure at the exhaust port 44 decreases, the nozzle 51 is closed by the compression force of the setting spring 53 via the second diaphragm 54 and the third diaphragm 55. Then, the nozzle back pressure increases, so the first diaphragm 47
is pressed down, and as a result, the main pulp 42 is opened, and air flows from the air supply port 43 to the exhaust port 44. in this way,
The railulator shown in FIG. 5 responds sensitively to pressure fluctuations on the secondary side and functions to always maintain the secondary side pressure constant relative to the set pressure.

Next, the operation of this embodiment will be explained. During measurement, the lower end of the Zorozho shaft 6 is held in the hand and the measuring stylus 5 is moved in a three-dimensional direction and successively brought into contact with the object to be measured.

Then, the measuring point 5 touches the object to be measured at points X and Y.

After each position in the Z-axis direction is detected by a detector (not shown), it is displayed on a display or the like.

Now, shaft material 13. Holder 16. Measuring head 5. cylinder 19
When the shaft member 13 is raised while air pressure balanced with the total weight of the cylinder head 20 is being supplied into the cylinder 19, the volume within the cylinder 19 increases and its internal pressure begins to decrease. Then, when the secondary pressure decreases below the set pressure due to a decrease in the internal pressure of the cylinder 19, the second regulator 35 operates the main pulp 42 in the direction of opening based on the above-mentioned operation, thereby increasing the secondary pressure, that is, the cylinder 19. maintain the internal pressure at the set pressure.

On the other hand, when the shaft member 13 is lowered from the balanced state,
The volume inside the cylinder 19 decreases and its internal pressure begins to rise. Then, when the secondary side pressure rises above the set pressure, the second regulator 35 operates the main valve 42 in the direction of closing based on the above-mentioned operation, releases excess air to the outside through the escape hole 60, and closes the cylinder. 19 is maintained at the set pressure.

In this way, since the weight of each member 9 constituting the prog shaft 6 is balanced by air pressure, the prog shaft 6 can be operated in the vertical direction with a relatively light force during measurement.

Therefore, according to this embodiment, since the weight of the shaft material 13 constituting the prong shaft 6 is balanced by the air pressure of the cylinder device 17, it is possible to reduce the weight compared to the conventional counterweight method. Speed-up can be achieved without adversely affecting measurement accuracy. In addition, since the cylinder device 17 is provided in the hollow hole 12 of the shaft member 13, the overall size can be reduced, and when considering the weight of the cover and mounting members, it is also lighter than the air cylinder method. can do.

In particular, in this embodiment, the air pressure of the cylinder device 17 is maintained constant by the second regulator 35, so when compared with the conventional air cylinder system that constantly supplies air to the cylinder to balance it, the pressure It has the advantage of excellent responsiveness to fluctuations and no air consumption in the balanced state.

In addition, since the system is balanced by the air pressure of the cylinder device 11, even if the measuring element 5 of various shapes and weights is attached to the shaft member 13 depending on the measurement item, for example, the measuring element 5 can be balanced by adjusting the air pressure. It can be made to correspond to the weight change of 5.

Further, the cylinder 19 of the cylinder device 17 is integrated with the shaft member 13 via the connection plate 18, and the upper end of the piston rod 22 is attached to the Zoracket 23 attached to the slider 4 so that the cylinder 19 can be displaced in the radial direction. , shaft material 13
The piston rod 22 can be supported without being hindered in raising and lowering the cylinder 19 based on the sliding surface of the cylinder 19, and the assembly work at that time can be performed simply and easily.

In addition, since the shaft member 13 is square, the shaft member 13 does not rotate in the horizontal direction, so that the orientation of the probe 5 can always be maintained at a constant orientation. In addition, the shaft material 13
Since air pads 14 are provided on each surface of the shaft member 13, the shaft member 13 can be moved up and down smoothly.

In addition, in practice, if the piston rod 22 is made sufficiently thinner than the piston rod of a normal cylinder and has flexibility, the piston rod can be made to fit in the cylinder 19.
The same effect can be achieved even without a structure for movably supporting the diaphragm in the radial direction. In this case, it is conceivable that the piston rod 22 be made of a flexible material from the beginning.

Further, the pressure regulating device may use hydraulic pressure in addition to the one that uses air pressure as described in the above embodiment.

On the other hand, in the above embodiment, the probe axis of a coordinate measuring machine was targeted, but the present invention can be applied to other equipment than the above-mentioned coordinate measuring machine as long as it has an axis that moves up and down. The prologue may be automatically driven according to a predetermined procedure.

As described above, according to the present invention, it is possible to provide a balance device for a measuring machine that is lightweight and can be downsized.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a three-dimensional measuring machine showing an embodiment of the present invention, Fig. 2 is a cross-sectional view showing the internal structure of the prong shaft, Fig. 3 is a cross-sectional view taken along the line ■-■ in Fig. 2, FIG. 4 is a circuit diagram showing the pressure regulating device, and FIG. 5 is a T sectional view showing the internal structure of the regulator. 4°°°Slider as structural body, 13...Shaft member, 1
7-°゛Cylinder device 19... cylinder, 21...
Piston, 22... Piston Rondo, 30... Pressure adjustment device. Agent Patent attorney Minoru Kinoshita (and 1 other person) Figure 1 Figure 2 几75 Figure 3 5 Figure 5-6-

Claims (1)

[Scope of Claims] (1) A hollow shaft member with a measuring element attached to the lower end is provided in the structure so as to be movable in the vertical direction, and a cylinder consisting of a cylinder, a piston, and a piston rod is installed inside the shaft member. The device is inserted into the cylinder, and the cylinder and the shaft member are integrally connected, and the upper end of the piston rod is supported by the structure, and the pressure fluctuation inside the cylinder due to the vertical movement of the cylinder is kept within a certain pressure. A balance device for a measuring machine, characterized in that it is equipped with a pressure regulating device that controls the pressure. (2. In claim 1, the balance device for a measuring machine is characterized in that the upper end of the piston rod is supported by the structure so as to be displaceable in the radial direction of the cylinder. (8) ) The balance device for a measuring machine according to claim 1 or 2, wherein the piston rod is made of a flexible material.