JP3228034B2 - Honing method and apparatus, and main shaft structure of honing machine used in the method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a honing method and a honing method for honing a hole in a workpiece and a main shaft structure of a honing machine used in the honing method.

More specifically, a honing method and apparatus for performing honing by correcting the surface pressure of a plurality of grindstones provided in a honing head for performing honing of a processing hole so that the surface pressure is always substantially constant, and honing. The present invention relates to a structure of a spindle in a panel.

[0003]

2. Description of the Related Art Conventionally, a honing machine for honing a machined hole (work) is shown in FIG.
The configuration is as shown in FIG.

That is, the honing apparatus has a configuration including a honing head 1 inserted into a processing hole in a work (not shown), and a drive system 3 that rotates the honing head 1 and reciprocates vertically. is there.

The honing head 1 is provided with a cylindrical head body 5, and a plurality of slits 7 are provided in the head body 5 at appropriate intervals in the circumferential direction. And
A plate-shaped grinding wheel shoe 11 having a grinding wheel 9 on the outside is fitted and mounted in each slit 7 so as to be movable in the radial direction.

A plurality of guide members 13 made of carbide or the like are provided on the peripheral surface of the head main body 5 at appropriate intervals in the circumferential direction. An air nozzle 15 is provided. The air micrometer blows air from the air nozzle 15 into a gap between the surface of the guide member 13 and the inner peripheral surface of the processing hole, and detects a change in air pressure at that time to detect the size of the gap. Things.

In order to move the grinding wheel shoe 11 in the radially outward direction and press the grinding wheel 9 against the inner peripheral surface of the processing hole, an expansion rod 17 is provided in the head body 5 so as to be vertically movable. The whetstone shoe 11 is attached to the rod 17.
Is provided with a tapered portion 19 for moving in the radial direction.

At the top of the head body 5, there is provided a mounting portion 23 for the drive system 3 to the main shaft 21.
Upper end 25 of the extension rod 17 projecting upward from
A return elastic body 29 such as a coil spring for returning the extension rod 17 to the original position is elastically mounted between the flange 27 attached to the mounting member 23 and the spring seat formed on the attachment portion 23.

The drive system 3 is composed of the main shaft 21 and the like which are rotatably driven and vertically movable on a honing machine (not shown). Said extension rod 17 against body 29
Is provided with a fluid pressure cylinder 31 for pressing and descending.

The fluid pressure cylinder 31 has a piston 33
The piston rod 33 </ b> R extending downward from the piston 33 is provided so that the lower end thereof abuts on the upper end 25 of the expansion rod 17.

In the above-described configuration, the honing head 1 is mounted on the main shaft 21, and the honing head 1 is inserted into the machining hole of the work. Then, the working fluid is supplied to the fluid pressure cylinder 31 to lower the piston 33, and the expansion rod 17 is pressed and lowered by the piston rod 33R, so that the grindstone shoe 11 is expanded in the radially outward direction by the action of the taper portion 19. The grinding stone 9 is pressed against the inner peripheral surface of the processing hole.

As described above, the main shaft 21 is rotated and vertically driven in a state where the grindstone shoe 9 is pressed against the inner peripheral surface of the processing hole, thereby performing the honing processing of the processing hole.

[0013]

As described above, when the expansion rod 17 is lowered by the piston rod 33 of the fluid pressure cylinder 31, the return elastic body 29 is compressed and acts as a reaction force. Therefore, the hydraulic cylinder 31
The pressure on the upper chamber side of P is P, the pressure receiving area of the piston 33 is A,
The angle of the tapered portion 19 is 2θ, the area where the grindstone 9 contacts the inner peripheral surface for the processing hole is a, the spring constant of the return elastic body 29 is k,
Assuming that the amount of deflection of the return elastic body 29 is X, the surface pressure Q of the grindstone 9 is given by the following equation.

[0014]

Q = (P · A−kX) / a · tan2θ (1) As is apparent from the above equation, when the grinding stone 9 is worn and the movement amount of the extension rod 17 is increased, the elastic body 29 is increased. Gradually increases, and the surface pressure of the grindstone 9 gradually decreases. When the surface pressure of the grindstone 9 decreases, the cutting (grinding) efficiency of the grindstone 9 tends to decrease, and there is a problem in improving efficiency.

[0015]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and the honing method according to the present invention described in the first aspect comprises the steps of: It moves outward in the radial direction by the tapered part provided on the expansion rod that is vertically movable inside,
In performing the honing process by pressing each of the whetstones against the inner peripheral surface of the processing hole of the workpiece, a fluid for lowering the expansion rod against a return elastic body for returning the expansion rod to its original position. This is a honing method in which a pressure corresponding to a reaction force due to elastic deformation of the elastic body is applied to the pressure of the pressure cylinder, and the surface pressure of each of the grindstones is constantly controlled to be substantially constant to perform honing.

In the honing apparatus according to the second aspect of the present invention, an extension rod is provided on the honing head so as to move up and down in order to move a plurality of whetstones provided on the honing head in a radially outward direction. In a honing apparatus including a return elastic body for returning to an original position and a fluid pressure cylinder for lowering an expansion rod against the elastic body, an amount of elastic deformation of the elastic body is detected. An amount of deformation detecting means, a calculating means for calculating a correction pressure to be applied to the fluid pressure cylinder based on a value detected by the amount of deformation detecting means, and a connection to the fluid pressure cylinder based on a calculation result by the calculating means. And control means for controlling the pressure control valve described above.

In the invention described in the third aspect, the deformation amount detecting means is configured to detect a movement amount of a piston rod or a piston in the hydraulic cylinder.

According to the invention described in the fourth aspect, the amount of movement of a piston or a piston rod in a fluid pressure cylinder provided on the main shaft of a main shaft of a honing machine having a mounting portion for mounting a honing head at a tip portion is described. 4 shows a main shaft structure of a honing machine provided with a detecting means for detecting.

[0019]

According to the honing method of the present invention described in the first aspect, the plurality of grinding wheels provided in the honing head are moved radially outward by a tapered portion provided on an extension rod provided inside the honing head so as to be vertically movable. When performing the honing by pressing each of the whetstones against the inner peripheral surface of the processing hole of the workpiece, for lowering the expansion rod against a return elastic body for returning the expansion rod to its original position. Since it is a machining method in which honing is performed by applying a pressure corresponding to a reaction force due to the elastic deformation of the elastic body to the pressure of the fluid pressure cylinder to constantly control the surface pressure of each of the grinding wheels to be substantially constant, When the amount of wear increases and the descending amount of the expansion rod increases, and the amount of elastic deformation of the elastic body increases, a pressure corresponding to the reaction force caused by the elastic deformation of the elastic body is applied to the fluid pressure cylinder.

That is, the fluid pressure cylinder is increased in pressure by an amount corresponding to the reaction force of the elastic body, and cancels the reaction force of the elastic body.

Therefore, the reaction force caused by the deformation of the elastic body is canceled, and the surface pressure of the grindstone is always kept substantially constant, so that the grinding efficiency does not decrease.

In the honing apparatus according to the second aspect of the present invention, an extension rod is provided on the honing head so as to be movable up and down so as to move a plurality of grindstones provided on the honing head in a radial direction. In a honing apparatus comprising a return elastic body for returning to the position of (2) and a fluid pressure cylinder for lowering the expansion rod against the elastic body, the amount of elastic deformation of the elastic body is detected. Deformation amount detecting means, calculating means for calculating a correction pressure to be applied to the fluid pressure cylinder based on a value detected by the deformation amount detecting means, and connected to the fluid pressure cylinder based on a calculation result by the calculating means. Control means for controlling the pressure control valve.

Therefore, when the expansion rod is lowered by the fluid pressure cylinder to perform the honing, the deformation amount of the elastic body deformed by the expansion rod is detected by the deformation amount detecting means, and the elastic body is detected based on the detected value. Is calculated, and the pressure control valve is controlled to apply a pressure corresponding to the reaction force to the fluid pressure cylinder.

Therefore, the pressure on the fluid pressure cylinder is increased by an amount corresponding to the reaction force of the elastic body, and cancels the reaction force of the elastic body.

Therefore, the surface pressure of the grindstone is always kept substantially constant regardless of the amount of deformation of the elastic body.

In the invention described in the third aspect, since the deformation amount detecting means detects the movement amount of the piston rod or the piston in the fluid pressure cylinder, the honing head itself is attached to and detached from the main shaft of the honing machine. Even if it is replaced, the deformation amount of the elastic body can be detected without causing any problem, and the pressure control of the fluid pressure cylinder based on the detected value can be easily performed. It is easy to control the surface pressure of the grindstone to be almost always constant.

According to the invention described in the fourth aspect, the amount of movement of a piston or a piston rod in a fluid pressure cylinder provided on the main shaft of a main shaft of a honing machine having a mounting portion for mounting a honing head at a tip end portion is described. Since the main shaft structure is provided with a detecting means for detecting, it is possible to easily detect the deformation amount of the return elastic body in the honing head mounted on the main shaft.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following, portions having the same functions as those of the above-described conventional configuration will be denoted by the same reference numerals, and redundant description will be omitted.

Referring to FIG. 1, a pressure source 41 such as a hydraulic pump and the upper and lower pressure chambers 31 of a hydraulic cylinder 31 are shown.
A switching valve 43 is connected to the fluid pressure circuit connecting U and 31L. A circuit 45 connecting the switching valve 43 and the upper pressure chamber 31U includes a switching valve 43 from the pressure chamber 31U side.
A check valve 47 for allowing the flow of the working fluid to the side is connected, and a pressure control valve 49 for maintaining the pressure on the secondary side at an adjusted set pressure is connected to the check valve 47.

A linear scale 5 is provided at an appropriate position of the piston rod 33R in the fluid pressure cylinder 31.
The linear scale 51 is provided on the main shaft 21.
Is provided with a sensor 53 for detecting the amount of movement of.

The sensor 53 includes a piston rod 33R.
The linear scale 51 is provided with a magnetically or optically memory corresponding to the sensor 53.

The detection signal or detection value of the sensor 53 is
This is input to the calculating means 57 in the control means 55 for adjusting the set pressure of the pressure control valve 49. The calculating means 57 calculates a deformation amount (bending amount) X of the return elastic body 29 based on a detection signal from the sensor 53, and calculates P ₂
= KX / A and by calculating those for calculating a correction pressure P ₂ to impart to the fluid pressure cylinder 31.

The control means 55 is provided with the arithmetic means 5
Based on 7 of the result, the pressure P obtained by adding the correction pressure P ₂ at the set pressure P ₁ of the pressure control valve 49 (P = P ₁ + P ₂₎ is supplied to the pressure chamber 31U of the upper hydraulic cylinder 31 Thus, the pressure control valve 49 is controlled.

Therefore, according to this embodiment, the honing head 1 is inserted into the machining hole of the workpiece to perform the honing operation, so that the pressure chamber 3 on the upper side of the fluid pressure cylinder 31 is operated.
When the working fluid is supplied to 1U to lower the piston 33, the expansion rod 17 is pressed and lowered by the piston rod 33R, and the tapered portion 19 provided on the expansion rod 17 is provided.
As a result, the grindstone shoe 11 is moved in the radially outward direction, and the grindstone 9 is pressed against the inner peripheral surface of the processing hole.

When the lowering of the piston 33 is stopped by the grinding wheel 9 being pressed against the inner peripheral surface of the machining hole, the pressure in the upper pressure chamber 31U of the fluid pressure cylinder 31 is increased by the pressure set by the pressure control valve 49. Is equal to

The surface pressure Q of the grindstone 9 at this time is given by the above-mentioned equation (1). Therefore, when the movement amount of the extension rod 17 gradually increases in accordance with the wear of the grinding stone 9, the deformation amount X of the return elastic body 29 for returning the extension rod 17 is increased.
And the reaction force (kX) also increases, so that the surface pressure Q of the grindstone 9 tends to gradually decrease.

Therefore, in this embodiment, the linear scale 51 and the scale 53 detect the amount of deformation X by which the expansion rod 17 is lowered by the piston rod 33 of the fluid pressure cylinder 31 to deform the elastic body 29. The calculating means 57 calculates the reaction force kX based on the detected deformation amount X and calculates the corrected pressure P ₂ (P ₂ = kX /
A) is calculated.

Based on the calculation result, the control means 55
The set pressure of the pressure control valve 49 is controlled so that the pressure on the next side of the pressure control valve 49 becomes a pressure P (P = P ₁ + P ₂ ) obtained by adding the correction pressure P ₂ to the initial set pressure P _1. .

Therefore, the pressure in the upper pressure chamber 31U of the fluid pressure cylinder 31 is equal to the correction pressure P for canceling the reaction force kX caused by the deformation amount X of the return elastic body 29.
_The pressure has been increased by ₂ minutes. Therefore, the surface pressure of the grindstone 9 is always kept substantially constant.

In order to detect the deformation X of the return elastic body 29, since the lower end of the piston rod 33R of the fluid pressure cylinder 31 and the upper end 25 of the expansion rod 17 are in contact with each other, What is necessary is just to detect the position where the piston rod 33R starts moving and the position where it stops, and calculate the difference.

As understood from the above description,
In the present embodiment, the amount of movement of the expansion rod 17 in the honing head 1 can be detected by detecting the amount of movement of the piston rod 33R in the fluid pressure cylinder 31. The movement limit value of the extension rod 17 or the piston rod 33R may be set in advance in accordance with the value, and an alarm may be output when the movement limit value is detected.

By exchanging the grindstone 9 in the honing head 1 when the above alarm is output, the management of tool exchange is facilitated, and excessive wear of the grindstone 9 may damage the machined surface. It is something that never happens.

Further, a correction pressure corresponding to the amount of deflection of the return elastic body 29 equal to the amount of movement of the expansion rod 17 is applied to the upper pressure chamber 31U of the fluid pressure cylinder 31. , A pressure sensor may be connected to the pressure chamber 31, and an alarm may be output when the detected value of the pressure sensor reaches a predetermined set value.

FIG. 2 shows a second embodiment, in which the position of the piston 33 is detected by a sensor 53A. The configuration for detecting the position of the piston 33 can be implemented by providing a permanent magnet for the piston 33 and using a magnetic sensor for the sensor 53A.

Since the other structure is the same as the structure shown in the first embodiment, the same effects can be obtained.

In the above embodiment, the case where the piston rod 33R of the fluid pressure cylinder 31 and the expansion rod 17 of the honing head 1 are in contact from the beginning has been described.

However, when the piston rod 33R and the expansion rod 17 are not in contact with each other from the beginning, a pressure sensor for detecting the pressure in the upper pressure chamber 31U of the hydraulic cylinder 31 is provided. During the downward movement of the piston rod 33R, the pressure rise of the pressure chamber 31U when the piston rod 33R comes into contact with the expansion rod 17 and tries to push it down against the elastic body 29 is detected. By using the detection position of the sensor 53 at the time of detecting the pressure rise as a reference, the amount of bending of the elastic body 29 can be easily detected.

Further, it is also possible to provide a detection means for detecting the vertical movement position of the expansion rod 17 in each honing head.

[0049]

As will be understood from the above description of the embodiment, according to the honing method of the present invention described in the first item, for example, the wear amount of the grindstone in the honing head is increased and the extension rod The descending amount of
When the amount of elastic deformation of the elastic body increases, the pressure corresponding to the above-described reaction force is applied to the fluid pressure cylinder in order to prevent the reaction force due to the elastic deformation of the elastic body from increasing and the surface pressure of the grindstone from decreasing. Granted.

That is, the fluid pressure cylinder is increased in pressure by an amount corresponding to the reaction force of the elastic body to cancel the reaction force of the elastic body, so that the surface pressure of the grindstone is always kept substantially constant. In addition, the grinding efficiency does not decrease.

According to the honing apparatus of the present invention described in the second aspect, when the extension rod of the honing head is lowered by the fluid pressure cylinder to perform the honing, the elastic body deformed by the extension rod is deformed. The amount is detected by the deformation amount detecting means, and the reaction force of the elastic body is calculated based on the detected value. Then, the pressure control valve is controlled to apply a pressure corresponding to the reaction force to the fluid pressure cylinder.

Therefore, the pressure on the hydraulic cylinder is
The pressure is increased by the amount corresponding to the reaction force of the elastic body,
The reaction force of the elastic body is offset, and the surface pressure of the grindstone is always kept substantially constant regardless of the deformation amount of the elastic body.

Therefore, good honing can always be performed without lowering the grinding efficiency.

In the invention described in the third aspect, since the deformation amount detecting means detects the movement amount of the piston rod or the piston in the fluid pressure cylinder, the honing head itself is attached to and detached from the main shaft of the honing machine. Even in the case of replacement, the deformation amount of the elastic body can be easily detected without causing any problem. Therefore, the pressure control of the fluid pressure cylinder based on the detected value can be easily performed, and the surface pressure of the grindstone provided in the honing head can be easily controlled to be almost always constant.

In the invention described in the fourth aspect, the main shaft of the honing machine having a mounting portion for mounting the honing head at the distal end thereof has a movement amount of a piston or a piston rod in a fluid pressure cylinder provided on the main shaft. Since the detection means is provided for detection, the amount of deformation of the return elastic body in the honing head mounted on the main shaft can be easily detected, and the surface pressure of the grinding stone of the honing head is almost always constant. It can contribute to holding.

[Brief description of the drawings]

FIG. 1 is a schematic illustration of a honing apparatus according to a first embodiment of the present invention.

FIG. 2 is a schematic explanatory view of a honing apparatus according to a second embodiment of the present invention.

FIG. 3 is an explanatory view schematically showing a conventional honing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Honing head 5 Head body 9 Grinding stone 11 Grinding stone shoe 17 Expansion rod 19 Taper part 29 Returning elastic body 31 Fluid pressure cylinder 33 Piston 33R Piston rod 49 Pressure control valve 51 Linear scale 53 Sensor 55 Control means 57 Calculation means

Claims (4)

(57) [Claims] 1. A plurality of grindstones provided on a honing head are moved radially outward by a tapered portion provided on an extension rod provided inside a honing head so as to be movable up and down. In performing the honing process by pressing against the surface, the elastic body of the elastic body is subjected to the pressure of the fluid pressure cylinder for descending the extension rod against the return elastic body for returning the extension rod to the original position. A honing method comprising: applying a pressure corresponding to a reaction force due to deformation to constantly control the surface pressure of each of the grindstones to a constant value to perform honing. 2. An extension rod is provided on the honing head so as to be movable up and down to move a plurality of grindstones provided on the honing head in a radially outward direction, and a return elastic body for returning the extension rod to an original position is provided. A honing apparatus including a fluid pressure cylinder for lowering an expansion rod against the elastic body; a deformation amount detecting means for detecting an elastic deformation amount of the elastic body; Computing means for computing a correction pressure to be applied to the fluid pressure cylinder based on the detected value of the fluid pressure cylinder, and control means for controlling a pressure control valve connected to the fluid pressure cylinder based on the computation result by the computing means. A honing machine characterized by comprising: 3. The honing apparatus according to claim 2, wherein the deformation amount detecting means detects a movement amount of a piston rod or a piston in the hydraulic cylinder. 4. A detecting means for detecting a moving amount of a piston or a piston rod in a fluid pressure cylinder provided on a main shaft of a honing machine having a mounting portion for mounting a honing head on a tip thereof. A main shaft structure of a honing machine characterized by being provided.