JPS61130801A - Dial-indicating type measuring instrument - Google Patents

Abstract

PURPOSE:To assure reduction of dimensions and improve measuring accuracy, by interaction of rock fixed to a main body and driving pinion supported by a free-moving slider and rotation of a pointer of a dial indicator caused by the interaction. CONSTITUTION:Driving pinion 19 and pointer pinion 20 are fixed on a supporting member 22 unavailable for relative change of position and slider 3, rack 8 and energizing means are installed. And, when the slider 3 is displaced along the master scale 2, a pinion 19 is rotated by the rack 8, this rotation is transmitted to a pinion 20 through intermiate geavs 25, 26 allowing reading of a measured value by indication of a pointer 16. And, as on this occasion, the whole gear mechanism is swuung and energized by an energizing means 30 pressing the pinion 19 firmly against the rack 8, supporting strength of the pinion 19 becomes available. Further, as oblique engagement a of pinion 19 and rack 8 are avaided overall correct engagements are available, measuring accuvacy can be improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a dial indicator type measuring instrument, and particularly to a measuring instrument such as a caliper of the type in which a pointer is rotated by engagement of a rack and a pinion. It can be used for calipers and depth gauges that use pinions, for example.

[Background Art and Problems Therein] So-called dial-indicating measuring instruments such as dial-indicating calipers and depth gauges are known in which the pointer of the dial instructing section is rotated by a rack and pinion, and the measured value is indicated by this pointer. ing. Such a measuring device has advantages such as higher measurement accuracy and easier reading of measured values compared to a type that directly reads measured values from scales engraved on the main scale and the vernier scale of the slider. Widely popular.

Incidentally, the meshing structure of the rack and pinion in a dial indicator type measuring instrument can be roughly divided into a rack following type and a rack non-following type. The former applies a pressing force to the pinion to pressurize the pinion into engagement with the rack so that the pinion always follows the rack, while the latter applies no pressing force to the pinion and maintains the normal meshing state. Judging from the standpoint of permanently ensuring measurement accuracy, the rack-following type is superior.

To explain this specifically, even if the rack is finished with high precision, there may be slight warpage on the rack, and even if there is no defect in the manufactured rack, it may be damaged during the assembly of the measuring instrument or for many years. The use of measuring instruments may cause the rack to warp or cause the rack to be installed in a misaligned position. In the non-rack following type, both the rack and pinion are fixedly held on a stationary body and a moving body, so if the rack is warped, the engagement between the rack and pinion will fluctuate, which can cause measurement errors. However, in the rack-following type, the pinion follows the rack and there is no variation in the engagement between the two, so measurement accuracy can be maintained.

Fig. 4 shows a conventional structure of a rack following type, which also aims to reduce the size of the measuring instrument. 52 was inserted and engaged, and the pinion 51 was pressed against the rack 53 by the spring action of the suppressing member 52.

In conjunction with today's technological sophistication, measuring instruments that measure in minute length units are required to have extremely high measurement accuracy, and are also desired to have improved ease of handling. From this point of view, the conventional structure shown in FIG. 4 has the following drawbacks.

Since the pinion 51 is tiltably supported by a spherical bearing on the upper pinion shaft 51B, when the pinion 51 receives the pressing force of the pressing member 52, the pinion 51 tilts and meshes with the rack 53 in an inclined manner. Therefore, an error will occur in the engagement between the two in a narrow range, which will affect the measurement results. In particular, due to the inclined mesh, the pinion 5
Since the pinion 1 wears unevenly, smooth transfer of the pinion 51 is not performed, and noise and foreign objects are likely to be caught. Furthermore, if the rack 53 and the pinion 51 become disengaged due to foreign matter such as dirt getting caught in the rack 53 and the pinion 51, troublesome and difficult work such as inserting a thin plate between the rack 53 and the pinion 51 is required to re-engage the rack 53 and the pinion 51. Furthermore, in order to improve measurement accuracy, if the rotation of the drive pinion meshing with the rack is transmitted to the pointer pinion via an intermediate gear, the followability of the drive pinion to the rack, the intermediate gear, and the pointer must be It is necessary to ensure consistency with the pinion mesh.

[Object of the Invention] The present invention has been made in view of the above-mentioned conventional problems and to solve them.An object of the present invention is to ensure miniaturization in a rack-following type dial indicating measuring instrument. ,
We also aim to improve measurement accuracy, operability, and handling.
Our goal is to provide dial-indicating measuring instruments with enhanced practicality and product value.

[Means and effects for solving the problem] Therefore, the configuration of the present invention is such that a rack attached to a main body cooperates with a drive pinion supported by a slider that is movable with respect to the main body to move the drive pinion to the slider side. In a dial indicator type measuring instrument that rotates a pointer of a dial indicator, the drive pinion and the pointer pinion directly connected to the pointer are attached to a holding member so that their relative positions cannot be changed, and the holding member is attached to the pointer. Rotatably supported on the slider on the opposite side of the drive pinion with the pinion in between, thereby making it possible to rotate the entire drive pinion and pointer pinion held by the holding member with respect to the rack. In addition, the drive pinion is characterized in that the driving pinion is pressed against the rack by the urging means.

[Example] As is clear from Fig. 1, this example is for the case where the dial indicator type measuring device is /gisu l.A slider 3 having a U-shaped cross section is slidable on the main scale 2, which is the main body. An outside jaw 4 and an inside jaw 5 are integrally formed above and below one end of the main slider 2, and an outside jaw 6 and an inside jaw 6 are also formed above and below one end of the slider 3. A storage space 7 is provided. A main scale scale 2A is displayed at the bottom of the surface of the main scale 2, and a long groove 2B is formed in the longitudinal direction of the main scale 2 in the center of the surface. It has become. A rack 8 is attached to the main scale 2 in the long groove 2B, and this rack 8 is shaped like an oblate rod and has a length extending to near both ends of the main scale 2.

A clamp screw 9 is provided on the top surface of the slider 3 for fixing the slider 3 at any position on the main scale 2, and a clamp screw 9 is provided on the bottom end of the slider 3 to move the slider 3 and attach the outside screws 4, 6. Alternatively, a constant pressure feed wheel 10 is provided for applying the inner jaws 5, 7 to the object to be measured with a constant pressure. A dial indicator 11 is disposed on the front of the slider 3 so as to traverse the upper front surface of the main scale 2. A scale plate 14 and a transparent cover (not shown) are fixed to the outer frame 12, and a base plate 15 is fixed to the inner frame 13 at a distance from the scale plate 14. Outer frame 12
is rotatably fitted into the inner frame 13 so that the scale plate 14 can be zero-adjusted with respect to the pointer 16, and the outer frame 12 is provided with a clamp screw 17 for fixing the outer frame 12 at any rotational position.
Being ignored.

The inner frame 13 is attached to a case 18, and this case 18 is integrated with the slider 3.

Integration of the case 18 and the slider 3 is accomplished by forming the case 18 integrally with the slider 3, or by forming the case 18 separately and connecting it to the slider 3 with screws or the like. The case 18 has a circular front shape corresponding to the inner frame 13, and has a relatively large wall thickness as shown in FIG. As is clear from FIG. 2, a storage hole 18A is formed in the approximate center of the case 18, passing through the front surface of the case 18.
9, a pointer pinion 20 directly connected to the pointer 16, etc., and these driving pinions 19, pointer pinions 20, etc. are attached to a holding member 22 so that their relative positions cannot be changed. and is stored in the storage hole 18A. Therefore, necessary parts such as the holding member 22 are arranged within the space of the dial indicator 11, and the caliper 1 can be made smaller.

As shown in FIG. 3, the holding member 22 is composed of two plate-like holding bodies 23 and 24 spaced apart from each other, and the pinion shaft 19A of the drive pinion 19 and the pinion shaft 20A of the pointer pinion 20 are connected to these holding bodies. 23 and 24, it is rotatably supported by the holding member 22 at two locations. The drive pinion 19 is a pinion shaft 19 protruding from the holder 24 on the back side.
Since the drive pinion 19 is provided at the end of the rack A, the drive pinion 19 protrudes from the holding member 2z, and thereby the rack 8
It is designed to mesh with the

The pointer pinion 20 is between two holders 23 and 24.

is provided on the pinion shaft 20A, and the holder 2 on the front side
The pointer 16 is attached to an end 20B of a pinion shaft 20A that extends upward in FIG. The pinion shaft 19A is provided with two intermediate gears 25, 26 that mesh with the pointer pinion 20, and these intermediate gears 25, 26 magnify the rotation of the drive pinion 19 and transmit it to the pointer pinion 20, improving measurement accuracy. For this reason, the intermediate gears 25, 26 have a larger diameter than the pointer pinion 20. The reason why the number of intermediate gears is two 25.26 is to eliminate the backlash that occurs when the intermediate gear meshes with the pointer pinion when there is only one intermediate gear.
Therefore, one intermediate gear 25 is fixed to the pinion shaft 19A, while the other intermediate gear 26 is fixed to the pinion shaft 19A.
9A, and these intermediate gears 25, 28 are urged by a coil spring 27 in mutually opposite rotational directions.

The end 24B of the back side holding body 24 is bent and overlapped with the end 23A of the front side holding body 23, and the holding member 22 is bent at the overlapping end 22A.
is pivotally attached to the stepped portion 18B of the case 18 with a screw 28 so as to be freely rotatable. As a result, the case 18 is connected to the slider 3 as described above.
Since the holding member 22 is integrated with the slider 3, the holding member 22 is attached and supported by the slider 3. An end portion 22A of the holding member 22, which is pivotally connected to the case 18 with a screw 28, is connected to the pointer pinion 2.
This is the end on the opposite side of the drive pinion 19 with the drive pinion 19 in between.

By attaching the holding member 22 to the case 18 in this way, when the holding member 22 rotates around the screw 28, the circle drawn by the pinion shaft 20A of the pointer pinion 20; the arc locus can be shortened, so that the pinion shaft 20A A hole 14A in the scale plate 14 and a hole 1 in the base plate 15 through which the end 20B is inserted to attach the pointer 16 to the end 20B.
The size of 5A can be reduced.

When the holding member 22 is rotatably attached to the case 18 with a screw 28, the rotational resistance of the holding member 22 is adjustable. This can be achieved by, for example, tightening the screw 28 by interposing an elastic member 29 such as a disc spring or a spring washer between the screw 28 and the holding member 22 as shown in FIG. 3, and adjusting the tightening force. .

As shown in FIG. 2, a biasing means 30 is installed between the case 18 and the holding member 22. This biasing means 30 is for causing the driving pinion 19 to mesh with the rack 8 with a pressing force to make the caliper 1 a rack following type. In this embodiment, the biasing means 30 is constituted by a coil spring 31. ing. One end of the coil spring 31 is connected to the holding member 22.
The other end is locked to a screw 32. This screw 3
2 is housed in a recess 18C formed on the outer peripheral surface of the case 18, and the tip of a screw 32, to which the other end of the coil spring 3°l is locked, is inserted into a through hole 180 that connects the storage hole 18A and the recess 18c. The screw 3 is inserted into the storage hole 18A and faces the storage hole 18A.
2 is screwed with a nut 33 in the recess 18G, and as a result, both ends of the coil spring 31 are attached to the holding member 22 and the case 18, and the tensile force of the coil spring 31 causes the holding member 22 to tighten as shown in FIG. The drive pinion 19 is urged to rotate clockwise about 28, and the drive pinion 19 meshes with the rack 8 while being pressurized.

When a tool such as a wrench is inserted into the recess 18G from the outside and the nut 33 is rotated, the screw 32 moves back and forth, so that the tensile force of the coil spring 31, that is, the urging force of the urging means 30 can be adjusted. As a result, the meshing force between the drive pinion 19 and the rack 8 is adjusted, and the lifting of the drive pinion from the rack occurs when the biasing force cannot be changed and the meshing is small, and the drive that occurs when the meshing force is large. Each problem of increased transfer resistance of the pinion can be solved.

Further, in this embodiment, as described above, since the rotational resistance of the holding member 22 about the screw 28 can also be adjusted, the meshing force between the drive pinion 19 and the rack 8 can be finely adjusted. still,
After assembling the caliper l, for example, if the recess 18C is hermetically filled with a sealant to prevent the nut 33 from rotating naturally,
It becomes possible to prevent the biasing force of the biasing means 30 from fluctuating during use of the caliper 1.

The urging means 30 is arranged so that the center portion B of the driving pinion 19 is located on the line of the urging direction A of the urging means 30 in FIG. 2 when the driving pinion 19 and the rack 8 are engaged. By doing this, the drive pinion 19 is moved to the rack 8 by a pressing force of the same magnitude as the urging force of the urging means 30.
This is convenient for adjusting the urging force to apply an appropriate amount of pressing force to the drive pinion 19. By arranging the biasing means 30 so that the biasing direction A is perpendicular to the rack 8 when the drive pinion 19 and the rack 8 are engaged, all the biasing force of the biasing means 30 is applied to the rack 8. It can now be used to press the drive pinion 19.

When the slider 3 is moved along the main scale 2, the drive pinion 19 is rotated by the rack 8, and this rotation causes the intermediate gear 2 equipped with the backlash prevention mechanism to rotate.
5.26 to the pointer pinion 20, the pointer 1
Measured values can be read according to the instructions in step 6.

The holding member 22 includes the above drive pinion 19 and intermediate gear 2.
5.26, since the entire gear mechanism consisting of the pointer pinion 20 is held and the entire gear mechanism is rotationally biased by the urging means 30 to press the drive pinion 19 against the rack 8, the drive pinion is mounted on a spherical bearing. The supporting strength of the drive pinion can be made larger than that of the conventional one which is tiltable, and even if the drive pinion 19 approaches and separates from the rack 8, the intermediate gear 25° 26 provided on the same axis as the drive pinion 19 , meshing with the pointer pinion 20 can always be ensured.

In addition to the above, as described above, the drive pinion 19 is pressed against the rack 8 by the rotation of the holding member 22, and the drive pinion itself is not tilted and pressed against the rack. The driving pinion 19 is not engaged with the rack 8 in an oblique manner, and the drive pinion 19 is fully engaged with the rack 8 to obtain a normal meshing relationship, so that measurement accuracy can be improved.Furthermore, due to the full-scale engagement, the drive pinion 19 is fully engaged with the rack 8.
Since there is no uneven wear, even if the caliper 1 is used for a long period of time, the drive pinion 19 will smoothly transfer to the pinion 7 and 8.
There is no noisy noise. Furthermore, the drive pinion 1
If the drive pinion 19 and the rack 8 become disengaged due to foreign objects such as chips getting caught between the drive pinion 19 and the rack 8, the holding member 2
No matter which part of 2 is pressed, the drive pinion 19 is
8, the drive pinion 19 can be easily re-engaged with the rack 8, resulting in excellent handling and operability.

In this embodiment, the dial indicator type measuring instrument is a caliper, but the present invention can also be applied to a dial indicator type, for example, a depth gauge, and if necessary, the pointer can be rotated by cooperation of the rack and pinion. It can be applied with any type of measuring instrument. Further, in this embodiment, the biasing means is a coil spring, but the biasing means is not limited to this and may be of any type.
If necessary, any device that presses the drive pinion against the rack may be used. Therefore, the biasing force adjustment mechanism of the biasing means is not limited to that of this embodiment, and may be any arbitrary mechanism.Furthermore, the biasing means does not necessarily have to be able to adjust its biasing force. If it is freely adjustable as in the example, the above-mentioned effect can be obtained. The same applies to the rotational resistance of the holding member, and although it is not necessarily necessary to make the rotational resistance adjustable, the above-mentioned effect can be obtained if the rotational resistance is adjustable. Furthermore, instead of making both the urging force of the urging means and the rotational resistance of the holding member adjustable, only one of them may be adjustable.

[Effects of the Invention] According to the present invention, it is possible to improve measurement accuracy, ease of handling, and operability while ensuring downsizing of the measuring instrument, thereby increasing product value and improving practicality.

[Brief explanation of drawings]

FIG. 1 is a front view of the main parts of a caliper, which is a measuring instrument according to this embodiment, and FIG. 2 is an enlarged view of FIG. 1 with the pointer etc. removed.
FIG. 3 is a sectional view of FIG. 2, and FIG. 4 is a perspective view showing the structure of a conventional example. 2...Main scale which is the main body, 3...Slider, 8...
Rack, 11... Dial instruction section, 16... Pointer,
19... Drive pinion, 20... Pointer pinion, 2
2... Holding member, 28... Pivoting screw, 31... Biasing means, 32... Coil spring.

Claims (4)

[Claims] (1) A dial indicator type measuring device that rotates the pointer of the dial indicator provided on the slider side through the cooperation of a rack attached to the main body and a drive pinion supported by a slider that is movable with respect to the main body. The drive pinion and the pointer pinion directly connected to the pointer are attached to a holding member so that their relative positions cannot be changed, and the holding member is rotated to the slider on the opposite side of the drive pinion with the pointer pinion in between. 1. A dial indicator type measuring instrument, characterized in that it is provided with biasing means for supporting the drive pinion and pressing the drive pinion against the rack. (2) In claim 1, the biasing means is a coil spring, and the center of the drive pinion is located on a line in the biasing direction when the drive pinion and the rack are engaged with each other. A dial indicator type measuring instrument characterized in that one end of the coil spring is attached to the holding member and the other end is attached to the slider. (3) A dial indicator type measuring instrument according to claim 1 or 2, wherein the urging force of the urging means is adjustable. (4) In any one of claims 1, 2, and 3, the holding member is pivotally supported by the slider with rotational resistance adjustable. Dial indicator type measuring device.