CN107009212A - Grinding attachment - Google Patents

Abstract

The grinding device provided by the invention can perform high-precision double-sided surface grinding. In a grinding device for grinding double-end surfaces of a cylinder and a piston constituting a rotary compressor, a pair of rotating grindstones are arranged to face each other at intervals on the same rotation axis; Inserted between a pair of rotating grinding wheels; a rotating mechanism that rotates the carrier plate; a control unit that controls the actions of the rotating grinding wheel and the rotating mechanism, and the carrier plate is provided with a recess for holding a cylinder or a piston, and the control unit performs the following controls , that is, the carrier is rotated by the rotating mechanism, and the cylinder and the piston held in the concave portion are alternately subjected to double-end surface grinding by the rotating grinding wheel.

Description

Grinding device

technical field

The present invention relates to a grinding device capable of performing high-precision double-sided surface grinding.

Background technique

Conventionally, there is known a double-sided surface grinding process in which a grinding device including a pair of rotating grindstones arranged up and down and a carrier plate inserted between the rotating grindstones is used, and the upper and lower rotating grindstones are used to simultaneously grind a workpiece set on the carrier plate. Surface grinding of both end faces. For example, in the case of performing double-sided surface grinding on the cylinder 3 and piston 4 constituting the set of the rotary compressor 11 shown in FIG. processing. Therefore, after the grinding process, the thicknesses of the cylinder 3 and the piston 4 are measured separately, and feedback correction is performed based on the measurement data, and the cutting amount of the grinding wheel is adjusted through NC control to maintain the specified thickness dimension.

However, there is a problem that the machined cylinder is ground due to the thermal expansion or thermal displacement of the equipment casing due to the influence of external air and cooling medium, or the sharpness of the rotating grinding wheel constituting the double-sided surface grinding device changes during processing. 3 and the difference in thickness of the piston 4 produces a problem of deviation, and may increase the leakage loss of the compressor. Although the fitting operation of combining the cylinder 3 and the piston 4 is performed, the difference in thickness between the cylinder 3 and the piston 4 is about 4 μm in the range of variation.

For example, in a workpiece mounting device for a double-sided surface grinder disclosed in Patent Document 1 below, a pair of rotating brackets having recesses is rotatably arranged on a carrier plate that can be moved in and out between a pair of rotating grindstones. The pair of rotary frames are arranged within the range capable of simultaneous grinding in the carrier plate, the intermediate transmission gears are respectively engaged with the outer peripheral gears of the respective rotary frames, and the respective intermediate transmission gears are engaged with individual drive motors. That is, a pair of rotary frames can be rotationally driven by one drive motor, and the double-end surface grinding process can be simultaneously performed on two or more workpieces held by the rotary frames.

Patent Document 1: Japanese Patent Laid-Open No. 2000-271842

The aforementioned Patent Document 1 is a structure in which two types of members are simultaneously ground by the same device, and is not a structure in which grinding is performed alternately while checking the thickness dimension of the workpiece. For this reason, the difference in thickness between the cylinder and the piston after grinding may vary, and fitting work of parts in an assembly process may be required.

Contents of the invention

The present invention was made to solve the above-mentioned problems, and an object of the present invention is to provide a grinding device capable of performing high-precision surface grinding on both sides of a cylinder and a piston constituting a rotary compressor. Grinding process, and can suppress the variation range of the thickness difference between the cylinder and the piston after grinding.

As means for solving the above-mentioned problems, the grinding device of the present invention performs double-end grinding on the cylinder and the piston constituting the rotary compressor. a carrier plate inserted between the pair of rotary grindstones; a rotation mechanism that rotates the carrier plate; and a control unit that controls operations of the rotary grindstone and the rotary mechanism. Controlling that a concave portion for holding the cylinder or the piston is provided on the carrier plate, and the control unit performs control such that the carrier plate is rotated by the rotating mechanism and alternately rotated by the rotating grinding wheel. The cylinder and the piston held in the concave portion are subjected to double-end surface grinding.

Preferably, a vibration detection unit is provided which detects a vibration generated by a grinding load during machining of the cylinder or the piston, and the control unit controls the operation of the rotary grindstone based on a detection value of the vibration detection unit.

Preferably, a variation detection unit is provided that detects a variation of the cylinder or the piston with respect to a grinding load, and the control unit controls the operation of the rotary grindstone based on a detection value of the variation detection unit.

Preferably, the control unit performs control such that, when the grinding conveyance speed of the rotary grindstone is set to V0, a constant value of the machinability of the material of the cylinder and the piston is set to A1, and when the area to be ground is As, the grinding conveyance speed V0 is switched to the optimum grinding conveyance speed V=A1×V0÷As.

The grinding device of the present invention can rotate the carrier plate in the same device to alternately grind the cylinder and the piston held in the concave portion, so that even if the equipment casing is thermally expanded due to the influence of external air or cooling medium, for example, Even if thermal displacement or the sharpness of the rotating grindstone changes during processing, it is also possible to suppress the variation width of the difference in thickness between the cylinder and the piston.

In addition, each time the cylinder and piston are processed, the carrier plate is rotated to alternately repeat the supply and discharge of the cylinder and piston to the processing position. Therefore, for example, during the grinding of the cylinder, the thickness of the piston can be measured. Grinding is performed while fine-tuning the grinding conveyance of the rotating grinding wheel.

That is, since the grinding device of the present invention can perform high-precision grinding, it is possible to eliminate the fitting work required in the past, improve manufacturing efficiency, and further reduce and stabilize the leakage loss of the compressor.

Description of drawings

FIG. 1 is an enlarged perspective view schematically showing a main part of a grinding apparatus according to Embodiment 1 of the present invention.

Fig. 2 is a control block diagram of the grinding device according to Embodiment 1 of the present invention.

FIG. 3(A) is a diagram showing temporal changes in machining dimensional errors of cylinders and pistons machined by the grinding apparatus of the present invention, and FIG. 3(B) is a diagram showing distribution of machining dimensional errors.

4 is an enlarged perspective view schematically showing a main part of a grinding apparatus according to Embodiment 2 of the present invention.

5 is an enlarged perspective view schematically showing a main part of a grinding apparatus according to Embodiment 2 of the present invention.

Fig. 6 is a longitudinal sectional view schematically showing an example of the structure of a rotary compressor.

Explanation of reference numerals: 1... carrier plate; 2a... recessed part; 2b... recessed part; 2c... recessed part; 2d... recessed part; 3... cylinder; 4... piston; 7...rotary grinding wheel at the lower part; 8...acceleration sensor; 9...current sensor; 10...post gauge; 11...rotary compressor; 20...control unit; 60...upper spindle head; 70...lower spindle head; 100...grinding device .

detailed description

Embodiment 1

Next, Embodiment 1 of the grinding apparatus of this invention is demonstrated based on drawing.

FIG. 1 is an enlarged perspective view schematically showing a main part of a grinding apparatus according to Embodiment 1 of the present invention. Fig. 2 is a control block diagram of the grinding device according to Embodiment 1 of the present invention.

As shown in FIG. 1 , the grinding device 100 of Embodiment 1 realizes grinding the cylinder 3 and the piston 4 on both sides when grinding the cylinder 3 and the piston 4 used in the rotary compressor 11 (refer to FIG. 6 ). The deviation width of the thickness difference is formed as a high-precision grinding device within, for example, 2 μm.

The grinding device 100 is provided with: an upper rotary grindstone 6 and a lower rotary grindstone 7, which are disposed opposite to each other at intervals on the same rotation axis; a carrier plate 1, which is inserted between the upper rotary grindstone 6 and the lower rotary grindstone 7; The rotating mechanism 5 rotates the carrier plate 1 ; the control unit 20 controls the operations of the upper rotating grindstone 6 , the lower rotating grindstone 7 and the rotating mechanism 5 .

As shown in FIG. 1 , the upper rotary grindstone 6 and the lower rotary grindstone 7 are constituted by a cup shape having an annular grindstone surface. The upper rotary grindstone 6 is attached so as to be rotatable by an upper spindle head 60 that is rotationally driven by a motor or the like. In addition, the lower rotating grindstone 7 is attached so as to be rotatable by a lower spindle head 70 that is rotationally driven by a motor or the like. In addition, although detailed illustration is omitted, the upper spindle head 60 is supported vertically by a column provided with a conveying mechanism in the vertical direction. On the other hand, the lower spindle head 70 is fixedly assembled to the column. The rotational drive and the conveyance mechanism in the vertical direction are controlled by the control unit 20 .

The rotation directions of the upper rotary grindstone 6 and the lower rotary grindstone 7 can be rotated in the same direction or in different directions by rotational driving. In addition, the rotational direction, rotational speed, and grinding conveyance speed of the upper rotary grindstone 6 and the lower rotary grindstone 7 are appropriately changed according to the types and thicknesses of the cylinder 3 and the piston 4 .

The carrier plate 1 is horizontally oblong in plan view, and has a thickness to be inserted into a space provided between the upper rotary grindstone 6 and the lower rotary grindstone 7 . In addition, the shape of the carrier board 1 is not limited to embodiment shown in figure, It can change suitably in consideration of an implementation situation.

On the upper surface of the carrier plate 1, as shown in FIG. 1, when the carrier plate 1 is viewed from above, the circular recesses 2a, 2b that respectively hold the cylinder 3 and the piston 4 are symmetrically arranged around the rotating shaft 5a of the rotating mechanism 5. There are two settings. Of the two recesses 2a, 2b, the cylinder 3 is attached to one recess 2a, and the piston 4 is attached to the other recess 2b.

In addition, although detailed illustration is omitted, each recessed part 2a, 2b is respectively comprised so that it can rotate about a center axis as a rotation axis, and can rotate the cylinder 3 or the piston 4 attached to each recessed part 2a, 2b.

The carrier board 1 is fixed to the upper end portion of the rotating shaft 5a of the rotating mechanism 5 disposed at the center of the carrier board 1, and rotates integrally with the rotating shaft 5a by the operation of a rotating motor (not shown). Further, with the rotation of the carrier plate 1, the recesses 2a, 2b can be alternately arranged at the processing position between the upper rotary grindstone 6 and the lower rotary grindstone 7, and at an exchange position rotated 180 degrees from this position. That is, it is possible to measure the thickness dimension of the piston 4 attached to the recessed portion 2 b or to replace the piston 4 while grinding the cylinder 3 attached to the one recessed portion 2 a.

The control unit 20 is a controller, and is built in, for example, the upper spindle head 60 . The control unit 20 is provided with: CPU; RAM (random access memory), which stores various data; and ROM (read-only memory), which stores the rotation direction, the rotation speed, and the rotation speed of the upper rotary grindstone 6 and the lower rotary grindstone 7, and the rotation speed of the upper rotary grindstone 6. Grinding conveyance speed, a program for controlling the rotation mechanism 5 of the carrier plate 1, etc. (none of them are shown). The control unit 20 appropriately controls the rotation direction and rotation speed of the upper rotary grindstone 6 and the lower rotary grindstone 7 , and the cutting conveyance speed of the upper rotary grindstone 6 according to the program in the ROM.

In addition, it is preferable that the control unit 20 performs control such that when the grinding conveyance speed of the upper rotary grindstone 6 is set to V0, the constant value of the machinability of the material of the cylinder 3 and the piston 4 is set to A1. , when the area to be ground is As, the grinding conveyance speed V0 is switched to the optimum grinding conveyance speed V=A1×V0÷As. A1 is calculated using, for example, the ratio of the wear amount H0 of the grinding wheel when 1000 reference workpieces are processed to the wear amount H1 of the grindstone when 1000 target material workpieces are similarly processed.

As shown in FIG. 2 , the control unit 20 is connected to an input side of an acceleration sensor 8 as vibration detection means and a current sensor 9 as a fluctuation detection means. Furthermore, a driving mechanism for the upper rotating grindstone 6 , a driving mechanism for the lower rotating grindstone 7 , and a rotating mechanism 5 for the carrier plate 1 are connected to the output side.

The acceleration sensor 8 is attached to a rotary drive (such as a motor) that rotates the upper rotary grindstone 6 , and detects vibration generated by the grinding load of the cylinder 3 and the piston 4 during machining.

The current sensor 9 is attached to the power line of the rotary drive (motor etc.) which rotates the upper rotary grindstone 6, and detects the fluctuation|variation of the cylinder 3 and the piston 4 with respect to a grinding load.

The control unit 20, which detects signals from the acceleration sensor 8 and the current sensor 9, controls the rotation direction and rotation speed of the upper rotary grindstone 6 and the lower rotary grindstone 7, and the grinding transport speed of the upper rotary grindstone 6 based on the detected values. .

Next, the grinding operation of the grinding apparatus 100 will be briefly described.

First, for example, the thicknesses of the cylinder 3 and the piston 4 before grinding are measured with a pre-gauge, and the machining allowance for cutting by both end surface grinding is calculated. Then, based on the calculated results, the machining start position of the upper rotary grindstone 6 is adjusted by NC control, and the grinding load is controlled.

Next, the grinding process of the cylinder 3 and the piston 4 respectively attached to the two recessed parts 2a and 2b of the carrier plate 1 is performed. The grinding apparatus 100 performs double-sided surface grinding from the cylinder 3, for example, based on the data calculated above. The grinding operation is performed while adjusting the rotation direction and rotation speed of the upper rotary grindstone 6 and the lower rotary grindstone 7 by the control unit 20 , and adjusting the cutting conveyance speed of the upper rotary grindstone 6 . At this time, the cylinder 3 rotates by the self-rotating concave portion 2a.

In addition, during the grinding process, the control unit 20 adjusts the upper rotary grinding wheel 6 and the lower rotary grinding wheel 6 based on the vibration generated by the grinding load detected by the acceleration sensor 8 and the fluctuation of the grinding load detected by the current sensor 9 . The rotation speed and rotation direction of the grinding wheel 7, and the adjustment of the grinding transport speed of the upper rotating grinding wheel 6 is performed.

Next, when the grinding process of the cylinder 3 is completed, the control unit 20 moves the upper rotary grindstone 6 upward, rotates the carrier plate 1 by 180 degrees by the rotating mechanism 5, and supplies the recess 2b on which the piston 4 is attached to the machining position. Grinding of the piston 4 is then performed with the upper rotary grindstone 6 and the lower rotary grindstone 7 .

Once the grinding process is completed, the cylinder 3 discharged from the processing position is measured, for example, with a subsequent gauge 10, and when there is a deviation in size due to the wear and thermal displacement of the upper rotating grindstone 6 and the lower rotating grindstone 7, feedback is given. In the correction control, the grinding process is performed again after the grinding process of the piston 4 is completed. In this way, the thicknesses of the cylinder 3 and the piston 4 are measured, and the grinding process is alternately performed.

Here, the result after performing the grinding process of the cylinder 3 and the piston 4 using the grinding apparatus of this invention is shown in FIG.3(A) and FIG.3(B). FIG. 3(A) is a graph showing the time-dependent variation of machining dimensional errors of the cylinder 3 and piston 4 machined by the grinding device of the present invention, and FIG. 3(B) is a graph showing the distribution of machining dimensional errors.

In FIG. 3(A), the vertical axis represents the error of the machining dimension, and the horizontal axis represents the timing when the grinding process is performed. As shown in FIG. 3(A), the waveforms of the machining dimensional errors of the cylinder 3 and the piston 4 are basically the same. Therefore, as shown in FIG. 3(B), by assembling and supplying the cylinder 3 and the piston 4 that have been ground at various times as a set, it is possible to suppress the variation in the thickness difference between the cylinder 3 and the piston 4 .

Therefore, the grinding device according to the first embodiment can rotate the carrier plate 1 to alternately perform double-head grinding on the cylinder 3 and the piston 4 held by the recesses 2a and 2b in the same device. Thermal expansion or thermal displacement due to the influence of external air and cooling medium, or the sharpness of the upper rotary grindstone 6 and the lower rotary grindstone 7 changes during processing, and the variation width of the thickness difference between the cylinder 3 and the piston 4 can also be suppressed.

In addition, since the carrier plate 1 is rotated every time the machining of the cylinder 3 and the piston 4 is performed, and the supply and discharge of the cylinder 3 and the piston 4 are alternately repeated to the machining position, it is possible to measure, for example, the friction of the piston 4 while the cylinder 3 is being ground. The thickness can be ground while finely adjusting the grinding transport of the upper rotary grindstone 6 .

As a result, since high-precision grinding can be performed, fitting work required conventionally can be eliminated, manufacturing efficiency can be improved, and leakage loss of the compressor can be reduced and stabilized.

Moreover, based on the information measured by the acceleration sensor 8 and the current sensor 9, the actions of the upper rotary grindstone 6 and the lower rotary grindstone 7 are controlled, so the grinding area of the cylinder 3 and the piston 4 and the area to be removed can be flexibly dealt with. The change in volume and the hardness of the material are different, so it is possible to perform grinding with higher precision.

In addition, by setting the machining allowance for cutting by end surface grinding within 20 μm, harmful burrs will not be generated as a compressor, and deburring work can be eliminated in the post-process. That is, since it is possible to prevent drooping and dents in the edge portion due to the deburring work, it is effective in reducing the leakage loss of the compressor.

Embodiment 2

Next, Embodiment 2 of the grinding apparatus of this invention is demonstrated based on FIG.4 and FIG.5.

4 and 5 are enlarged perspective views schematically showing main parts of a grinding device according to Embodiment 2 of the present invention. In addition, in Embodiment 2, the difference from Embodiment 1 will be mainly described, and the same reference numerals will be attached to the same positions, and the description will be omitted.

In the grinding device 100 according to Embodiment 2, the carrier plate 1 is circular in plan view and has a thickness to be inserted between the upper rotary grindstone 6 and the lower rotary grindstone 7 . When viewing the carrier plate 1 from above, on the upper surface of the carrier plate 1, four circular recesses 2a to 2d for holding the cylinder 3 and the piston 4 are provided at intervals of 90 degrees around the rotating shaft 5a of the rotating mechanism 5. ,. In the case of Embodiment 2 shown in FIG. 4 , as an example, among the recesses 2a to 2d, the piston 4 is attached to the recesses 2a, 2c, and the cylinder 3 is attached to the recesses 2b, 2d.

The carrier plate 1 rotates integrally with the rotating shaft 5 a at intervals of 90 degrees by the operation of a rotating motor (not shown). With the rotation of the carrier plate 1 , the recesses 2 a to 2 d can be arranged at a processing position between the upper rotary grindstone 6 and the lower rotary grindstone 7 and at an exchange position rotated 90 degrees from this position. That is, during the grinding of the cylinder 3 attached to the recess 2a, the thickness dimension of the cylinder 3 or the piston 4 attached to the recesses 2b to 2d can be measured, or the cylinder 3 or the piston 4 can be replaced.

In addition, although detailed illustration is omitted, each recessed part 2a-2d is comprised so that it can rotate about a center axis|shaft as a rotation axis, respectively, and can rotate the cylinder 3 or the piston 4 attached to each recessed part 2a-2d.

Next, the grinding operation of the grinding apparatus 100 according to Embodiment 2 will be briefly described.

First, for example, the thicknesses of the cylinder 3 and the piston 4 before grinding are measured with a pre-gauge, and the machining allowance for cutting by both end surface grinding is calculated. Then, based on the calculated results, the machining start position of the upper rotary grindstone 6 is adjusted by NC control, and the grinding load is controlled.

Next, the grinding process of the cylinder 3 and the piston 4 respectively attached to the four recessed parts 2a-2d of the carrier plate 1 is performed. The grinding apparatus 100 performs double-sided surface grinding from the piston 4, for example, based on the data calculated above. The grinding operation is performed by adjusting the rotation speed and rotation direction of the upper rotating grindstone 6 and the lower rotating grindstone 7 and adjusting the cutting conveyance speed of the upper rotating grindstone 6 by the control unit 20 . At this time, the piston 4 is rotated by the self-rotating concave portion 2a.

In addition, during the grinding process, the control unit 20 adjusts the upper rotary grindstone 6 and the lower rotary grindstone based on the vibration generated by the grinding load detected by the acceleration sensor 8 and the fluctuation of the grinding load detected by the current sensor 9 . 7 rotation speed, rotation direction, and the adjustment of the grinding conveying speed of the upper rotary grinding wheel 6.

Next, when the grinding process of the piston 4 is completed, the control unit 20 moves the upper rotary grindstone 6 upward, rotates the carrier plate 1 by 90 degrees by the rotating mechanism 5, and supplies the concave portion 2b on which the cylinder 3 is attached to the machining position. Then, the cylinder 3 is ground with the upper rotary grindstone 6 and the lower rotary grindstone 7 . After that, the carrier plate 1 is further rotated, and the grinding process of the piston 4 attached to the recessed part 2c and the grinding process of the cylinder 3 attached to the recessed part 2d are sequentially performed.

Once the grinding process is completed, the cylinder 3 or piston 4 discharged from the processing position is measured, for example, with a subsequent gauge 10, and if there is a deviation in size due to the wear of the rotating grinding wheel or the influence of thermal displacement, feedback correction is performed. Control, after the grinding of all the cylinders 3 and pistons 4 is completed, the grinding is performed again. In this way, the thicknesses of the cylinder 3 and the piston 4 are measured and the grinding process is performed alternately.

In addition, in Embodiment 2 shown in FIG. 4 , the structure in which the cylinder 3 and the piston 4 are attached to the recesses 2 a to 2 d is shown, but as shown in FIG. 5 , only the cylinder 3 can be attached to the recesses 2 a to 2 d. or a structure in which only the piston 4 is attached to the recessed portions 2a to 2d, although detailed illustration is omitted.

That is, in the case of FIG. 5 , the grinding process of the cylinder 3 can be performed so as to have an optimum thickness with respect to the thickness of the piston 4 calculated in advance. As a result, since there is no need to process cylinders 3 or pistons 4 of different materials and hardnesses, abnormal wear and clogging of the grinding wheel can be prevented, and correction intervals can be extended, thereby improving productivity.

As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to the structure of said embodiment. For example, in Embodiments 1 and 2, the structure provided with the acceleration sensor 8 and the current sensor 9 has been described, but the double-end surface grinding process can be performed without the acceleration sensor 8 and the current sensor 9, and high-precision grinding can be realized sufficiently. processing. In addition, in Embodiments 1 and 2, although the structure in which two recessed parts 1 were provided and the structure in which four recessed parts were provided in the carrier board 1 were demonstrated, it is not limited to the said number. That is, for the sake of caution, it is supplemented that various changes, applications, and ranges of use by those skilled in the art as needed are also included in the gist (technical scope) of the present invention.

Claims (4)

1. A grinding device, which carries out double-end surface grinding to a cylinder and a piston constituting a rotary compressor, the grinding device is characterized in that it has: A pair of rotating grinding wheels, which are spaced apart from each other on the same rotation axis and arranged opposite to each other; a carrier plate inserted between the pair of rotating grinding wheels; a rotation mechanism that rotates the carrier plate; and a control unit that controls the operation of the rotating grinding wheel and the rotating mechanism, A recess for holding the cylinder or the piston is provided on the carrier plate, The control unit performs control such that the carrier is rotated by the rotation mechanism, and the cylinder and the piston held in the concave portion are alternately subjected to double-end surface grinding by the rotating grinding wheel. . 2. Grinding device according to claim 1, characterized in that, having a vibration detection unit that detects vibration generated by a grinding load during machining of the cylinder or the piston, The control unit controls the operation of the rotary grindstone based on the detection value of the vibration detection unit. 3. Grinding device according to claim 1 or 2, characterized in that, a variation detection unit is provided that detects a variation of the cylinder or the piston relative to a grinding load, The control unit controls the operation of the rotary grindstone based on the detection value of the fluctuation detection unit. 4. The grinding device according to claim 1 or 2, characterized in that, The control unit performs control such that when the grinding conveyance speed of the rotary grindstone is set to V0, a constant value of the machinability of the material of the cylinder and the piston is set to A1, and When the area to be ground is As, the grinding conveyance speed V0 is switched to the optimum grinding conveyance speed V=A1×V0÷As.