JPH064221B2 - Precision dressing device - Google Patents

Description

The present invention relates to a precision dressing device.

[Conventional technology and its problems]

Grinding wheels are widely used as a means for finishing tools, gauges and other hardened parts, and recently, especially for the processing of hard and brittle materials such as ceramics and the demand for improved grinding ability and finishing accuracy. CBN grindstones and diamond grindstones are often used.

By the way, as is well known, the grinding wheel grinds the work at a high speed, so the cutting edge of the abrasive grains wears due to mechanical load and physical / chemical action, and it is ground due to clogging, spilling, or crushing. The ability is reduced and the finished surface is deteriorated. In addition, the roundness of the grindstone deteriorates due to the vibration. Therefore, for grinding work,
Dressing for crushing dull abrasive grains to make a sharp cutting edge appear and truing for shaping the outer periphery of the grindstone into a desired shape are indispensable, and a dresser is used as a means for simultaneously performing these operations.

As this dresser, there are a single stone type and a multi-stone type in which a shaft end is filled with diamond, but since a good performance cannot be obtained, a rotary dresser in which diamond is electrodeposited on the outer circumference of the roller is used.

However, the conventional dressing device using the rotary dresser has a structure in which the shaft 2 is simply supported by the bearings 10 and 11 in the housing 1 and the rotary dresser 3 is fixed to the tip of the shaft 1 as shown in FIG. ,
The contact point (preparation) with the whetstone to be sharpened and shaped was examined by the sensitive detection method, in which the personnel checked the sparks and fricatives with their eyes and ears. Therefore, it requires a high degree of skill, yet the melting point detection accuracy is poor, the variation is large, and the depth of cut is often unnecessarily increased, increasing the consumption of expensive abrasive grains and increasing the grinding cost. There was a problem.

[Means for solving problems]

The present invention was created by research to solve the above problems, the purpose of the object is to be able to automatically detect the contact between the grindstone and the dresser, the contact detection performance is high, Moreover, it is an object of the present invention to provide a dressing device capable of stably maintaining its performance for a long period of time and capable of highly accurate dressing / shaping with a minimum necessary minute cut.

In order to achieve this object, the present invention provides a dressing device including a dresser, a shaft to which the dresser is attached, and a housing that rotatably supports the shaft. In the dressing device, an AE sensor is provided in the housing, and a liquid medium partially facing the shaft. A sealing chamber and means for applying pressure to the liquid medium sealing chamber are provided, and means for detecting the amount of liquid in the liquid medium sealing chamber is provided outside the housing.

〔Example〕

 Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1 and 2 show an example of a precision dressing device according to the present invention, in which 1 is a housing, and a shaft 2 is rotatably supported by bearings 10 and 11 at a central portion,
It is adapted to rotate at a required speed by a drive shaft 12, and a sleeve-shaped double spacer 1 is provided between the bearings 10 and 11.
While the inner races 3 and 14 are interposed, the inner race of the bearing 10 is held by a holding nut 15 screwed onto the shaft 2, and the outer race is held and fixed by a lid member 16 screwed onto the housing 1.

Reference numeral 3 denotes a rotary dresser, which is fixed to a tip portion of the shaft 2 protruding from the housing 1 by a fastening tool 31 such as a bolt or a nut, and a cutting edge 30 to which a diamond is fixed by a bond is provided on an outer peripheral surface of the tip.

4 is an AE sensor, that is, the grindstone B and the rotary dresser 3
Is a sensor for detecting ultrasonic vibration generated when it comes into contact with, and is housed in a hole portion 17 formed in the housing 1 in parallel with the shaft 2, and a detection surface is formed on a wall of the hole portion by a presser 18 fitted into the hole portion. 40 is fixed so as to be in close contact with each other, and the conductive wire 41 of the AE sensor 4 is guided to an external electric control device (not shown) through the through hole 19 of the pusher 18.

Reference numeral 5 is a liquid medium-filled chamber for effectively transmitting the ultrasonic vibration to the AE sensor 4. In the figure, the main path 50 bored in the housing 1 in a phase-shifted relationship with the hole 17 and the curved path 5 whose tip faces the outer peripheral surface of the shaft.
1 and a replenishment path 52 having one end communicating with the curved path 51 and the other end extending to the outer circumference of the housing. The seal material 20 that is in close contact with the outer peripheral surface of the shaft is provided at the portions corresponding to both sides of the curved path 51. , 21 are provided.

6 is a means for applying a constant pressure to the liquid medium in the liquid medium sealing chamber 5 to pressurize and supply the liquid medium to the outer peripheral surface of the shaft through the curved path 51, and is slidably inserted in the main path 50. A piston 60, a spring 61 that biases the piston 60 from the back, and an adjustment nut 62 that adjusts the set pressure of the spring 61 are provided, and a seal ring 63 is attached to the circumferential surface of the piston 60.

Reference numeral 7 is a means for externally detecting the amount of the liquid medium in the liquid medium sealing chamber 5, and a through hole 70 formed in the housing wall corresponding to the main path 50 and a screw on the outer surface of the housing including the through hole 70. A face plate 71 made of a transparent material or the like fixed by 73, the face plate 71 is provided with a liquid amount scale 72 calculated in advance from the correlation between the piston stroke and the pressure, and the transparent hole 70 has a transparent filling material (not shown). Is packed.

Reference numeral 8 is a replenishment portion with an on-off valve provided at the end of the replenishment passage 52, and 9 is an initial injection portion formed at a proper position of the replenishment passage 52.

[Operation of Example]

 Next, the operation and action of the embodiment of the present invention will be described.

In use, the liquid medium is supplied into the liquid medium sealing chamber 5 through the initial injection part 9, and this supply amount is the position of the piston 60 visually observed through the through hole 70 and the liquid amount scale 72 corresponding thereto. Can be easily confirmed by closing the initial injection part when the appropriate amount is reached.

Next, the present apparatus is set so that the shaft axis line is at a predetermined attachment angle with the grindstone B, and in this state, the grindstone B and the shaft 2 are rotated to feed the apparatus or the grindstone B at a predetermined speed. As a result, the cutting edge 30 of the rotary dresser 3 and the grindstone B come into contact with each other. At the moment of this contact, a unique ultrasonic vibration is generated, and this ultrasonic vibration is transmitted to the shaft 2 that fastens the rotary dresser 3 and is transmitted to the housing 1 via the liquid medium that is in contact with the outer peripheral surface of the shaft 2. And is detected by the AE sensor 4 fixed in the housing. The detection signal is input to the electric control device via the lead wire 41, from which a feed command parallel to the shaft 2 is sent to the grindstone B, and dressing is started.

According to the present invention, the AE sensor 4 is not simply embedded in the housing 1 to detect the ultrasonic vibration, but the ultrasonic vibration is detected via the liquid medium contained in the housing 1. Therefore, the vibration damping can be suppressed to the minimum. There is little pickup of intermediate noise. Moreover, the liquid medium is pressurized in the liquid medium sealing chamber 5 by the spring 61 and the piston 60, and is continuously supplied to the gap between the shaft 2 and the housing 1 through the main path 50 and the bent path 51. The contact point detection accuracy can be made extremely high. Further, since the liquid medium is not discharged, the consumption amount of the liquid medium is reduced, and the liquid is not scattered, so that the working environment is not impaired.

The liquid medium is prevented from leaking to the outside by the sealing materials 20 and 21, and even when the liquid amount decreases due to long-term use, the position of the piston 60 is visually observed through the through hole 70, so that the liquid amount can be instantly known. Therefore, when the lower limit of the liquid amount scale 72 is reached, the liquid is appropriately replenished by the replenishing unit 8 so that the pressurized supply of the liquid medium can be continued. Therefore, the previous AE sensor 4
The detection performance is stable over a long period of time, and high reliability can be maintained.

〔The invention's effect〕

According to the present invention described above, in the dressing device including the dresser, the shaft to which the dresser is attached, and the housing that rotatably supports the shaft, the AE sensor 4 in the housing 1 and the liquid partially exposed to the shaft 2. A medium containing chamber 5 and means 6 for applying pressure to the liquid medium containing chamber 5 are provided, and the liquid medium containing chamber 5 is provided outside the housing.
Since the means 7 for detecting the amount of the liquid is provided, the contact point between the grindstone and the dresser can be detected automatically and with high accuracy, and stable detection performance can be maintained for a long time. Excellent effects such as precise and economical sharpening and shaping can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the precision dressing device of the present invention, FIG. 2 is a plan view thereof, and FIG. 3 is a sectional view of a conventional dressing device. DESCRIPTION OF SYMBOLS 1 ... Housing, 2 ... Shaft, 3 ... Rotary dresser, 4 ... AE sensor, 5 ... Liquid medium enclosure chamber, 6 ... Liquid medium pressurizing means, 7 ... Liquid medium amount detecting means

Claims (1)

[Claims] 1. A dressing device comprising a dresser, a shaft to which the dresser is attached, and a housing rotatably supporting the shaft, wherein an AE sensor and a liquid medium enclosure chamber, a part of which faces the shaft, are arranged in the housing. A precision dressing device characterized in that a means for applying pressure to the liquid medium sealing chamber is provided and a means for detecting the amount of liquid in the liquid medium sealing chamber is provided outside the housing.