JPS5933539Y2 - Spindle device with built-in chuck - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spindle device with a built-in chuck that can chuck the central portion of a workpiece and process both ends thereof, and particularly relates to an improvement of the bearing portion of the spindle.

Conventionally proposed devices of this type rely on pressure oil supplied to the cylinder to lubricate the bearings that rotatably support the main shaft, which prevents the bearing from generating heat during high-speed rotation. It is not possible to cool the bearing, and there is a risk that dust and the like in the pressure oil may damage the bearing, and therefore, high precision machining may not be maintained.

The present invention was developed in view of the above circumstances, and an object of the present invention is to provide a spindle device with a built-in chuck that can sufficiently lubricate the bearing.

The feature of this invention is that both sides of the central part of the main shaft are rotatably supported by rolling bearings, and these rolling bearings are lubricated by a dedicated lubricating oil supply passage independent from the pressure oil supply mechanism. There is a particular thing.

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

In FIG. 1 showing an embodiment of the present invention, 1 is a headstock, and ball bearings 3, which are examples of rolling bearings, are inserted into recesses on both sides of the headstock 1 at predetermined intervals. The bearing retainer 5 and I are respectively tightened by bolts 9.11 on both sides of the headstock.

The bearing holders 5 and 7 each cover the bearing 3 and press and fix the respective outer rings.

Further, the main shaft 15 having a through hole 13 in the center has a small diameter portion 1
1. Consisting of a medium diameter portion 19 and a male threaded portion 27, the small diameter portion 1
7 is fitted into the inner rings of the pair of ball bearings 3.3 and a spacer 25 that regulates the distance between the inner rings.

A female threaded member 29 is screwed into a male threaded portion 27 formed at the left end in the figure, and this male threaded member 29 cooperates with a stepped portion 31 of the medium diameter portion 19 formed at the right end in the figure. The inner rings of the pair of ball bearings 3 and the spacer 25 are tightened and fixed.

The gap between the outer circumferential surface of the medium diameter portion 19 and the inner circumferential surface of the bearing retainer 5 is made oil-tight by a sealing member 33, and the oil reservoir 3 on the right side is
4 is maintained.

Additionally, a connecting body 20 is integrally connected to the tip (left end in the figure) of the male threaded portion 27 of the main shaft 15 with a bolt (not shown), and the outer diameter of this connecting body 20 is the same as that of the large diameter portion 21. , a small diameter portion 22 , and a medium diameter portion 23 .

The small diameter portion 22 of this coupling wheel 20 is connected to the bearing presser 7.
The oil reservoir 36 of the left ball bearing 3 is kept oil-tight by a sealing member 35 provided on the bearing presser 7 side of this penetrating portion.

A ring-shaped V pulley (rotating body for driving the main shaft) 37 is connected to the main shaft by an appropriate number of bolts 39 on the end face of the large diameter portion 21.
The inner circumferential surface 41 of this pulley 37 is fitted onto the outer circumferential surface of the medium diameter portion 23 .

The outer circumferential surface of the medium diameter portion 23 and the inner circumferential surface 41 of the pulley 37 are made liquid-tight by fitting into a sealing member 43 provided on the inner circumferential surface 41 side.

A cylinder pore 45 is formed in the center of this medium diameter portion 23, and a piston 47 is fitted into the pore 45.

The piston 47 includes a piston main body 49 and a piston follower 53, and the piston follower 53 is screwed so as to slide together with the piston main body 49.

In addition, the piston follower 53 is detachably attached to the main body 49, so that when the taper hole (described later) is worn out,
It can be replaced with new parts.

The circumferential surface of the connecting portion between the piston main body 49 and the piston follower 53, the outer circumferential surface of the large diameter portion of the main body 490, and the V boo IJ 3
Seal members 55, 57, and 59 provided on the inner circumferential surface of the web portion through hole of γ maintain oil tightness between the cylinder pore 45 and the piston 47.
is slidable in the axial direction within the cylinder pore 45 in an oil-tight state.

That is, the large diameter portion 21 and medium diameter portion 23 of the coupling body 200 and the V pulley 37 form a cylinder portion of the hydraulic cylinder.

The mallet body 53 of the piston 47 is provided with a through hole 61 having a size through which the workpiece W can be easily inserted, and a tapered hole portion 63 is formed at the right end of the mallet body 53 of the piston 47 in the figure. There is.

Further, the piston main body 49 is prevented from rotating relative to the V-pulley 37 by a pin 119.

A ring-shaped cover plate 65 is removably fixed to the right end of the main shaft 150 in the figure with bolts 67.
A tapered hole portion 69 is formed on the end surface of the plate 65 that is fitted into the through hole 13 so as to face the tapered hole portion 63 of the mallet body 53 of the piston 41 .

Inside the through hole 13, a cylindrical collet 71 with a thicker center portion is inserted into the pair of tapered hole portions 63 and 69.
Toni Hassan! It is placed in a vertical position.

The center part of this collet 71 has an outer diameter dimension that allows it to fit into the through hole 13, and a through hole γ3 slightly larger than the diameter of the workpiece W is located on the axis of the collet 71.
is formed.

The collet 71 has gripping claws 7 at its left and right ends.
5 and 77 are divided into a plurality of parts by slits cut in the axial direction, and tapered surfaces 79, 81 corresponding to these gripping claws 75, 77 are formed, respectively.

The spacer 25 described above has two rows of annular grooves 85 on the inner surface 83.
．． 87 is carved with annular grooves 91 and 93 at corresponding positions on the outer surface 89 of the spacer 25. At the corresponding position, there is also an annular groove 97.
99 are provided respectively.

The headstock 1 is provided with an oil supply port 4101, and this port 101 is connected to an oil passage 103 for pressure oil reaching the annular groove 99 and an oil passage 103 between the annular grooves 93 and 87.
5 and an oil passage 109 formed in the main shaft 15 to a pressure chamber 107 on the left side of the piston 41 (FIG. 1).

In addition, an oil supply port (not shown) provided at another position on the headstock is connected to an oil passage 111 for pressure oil that reaches the annular groove 97.
It communicates with the pressure chamber 115 on the right side of the piston 47 via an oil passage 113 between the annular groove 91.85 and an oil passage 117 formed in the main shaft 15.

When the main shaft 15 rotates, the outer surface 89 of the spacer 25 is configured to be able to slide and rotate relative to the headstock side sliding surface 95.

That is, in this embodiment, the spacer 25 is attached to the main shaft 1.
It also serves as an oil passage connecting member for communicating the oil supply port of the main shaft 15 with the cylinder portion regardless of the rotational phase of the shaft 5.

Two oil supply passages 123 and 125 for bearing lubrication, each having an oil supply port different from the pressure oil supply port, are formed in the headstock 1, and these oil supply passages 123 and 125 form a pair. It communicates with the inner and outer race spaces of the bearings 3, 3, respectively, and further communicates with the oil reservoirs 36 and 34, respectively, through this space.

In addition, two oil pipes for recovering lubricating oil from the bearings have a pressure oil supply port and a lubricating oil recovery port separate from the lubricating oil supply ports at positions other than the oil supply passages 123 and 125 of the headstock 1. Recovery passages 137 and 139 are formed, respectively, and these oil recovery passages 131 and 139 communicate with the oil reservoirs 36 and 34, respectively.

That is, in this embodiment, the oil supply passage 123,
125, inner and outer ring spaces of bearings 3, 3, oil sump 36,
34 and oil recovery passages 137 and 139 constitute a lubricating oil supply passage exclusively for lubricating the bearings 3, 3.

Therefore, the bearings 3, 3 can be sufficiently lubricated independently regardless of the operational status of the pressure oil supply mechanism described above.

That is, when the main shaft 15 is rotated at high speed, sufficient lubricating oil can be circulated through the bearings 3, 3 depending on the situation, so that the high heat generated during high speed rotation can be sufficiently cooled.

In addition, since it is independent from the pressure oil supply system, it is possible to use the most suitable special oil for lubrication (for example, spindle oil with a lower viscosity than oil for pressure oil), and for lubrication. It is possible to prevent dust from entering the oil.

However, this does not preclude the use of a pressure oil attachment as a lubricating oil.

Even when oil is shared in this way, the lubricating oil supply system is independent from the pressure oil supply system, so the lubricating oil system has its own cooling means, dust collection filter, flow rate, flow rate, etc.
A pressure regulating valve can be freely installed, and a considerable lubrication state can be ensured.

Now, if pressure oil is supplied to the oil supply port 101,
At the sliding surface between the outer surface 89 of the spacer 25 and the headstock side sliding surface 95, pressure oil leaks from the annular groove 91, 93°97.99.

This leaked pressure oil passes through the sliding surfaces 89 and 95 and attempts to reach the bearings 3, 3 at both ends.

By the way, in the past, the bearings 3, 3 were lubricated only by the pressure oil leaking into the bearings 3, 3, so it was not possible to ensure sufficient lubrication, and the sliding of the bearings 3, 3 It could not be avoided that the surfaces were damaged by dirt that may normally be present in pressure oil.

In particular, the spacer 25 is provided with a pressure oil outlet port (in this example, an annular groove 91,97).

) (also the left bearing 3) is not supplied with sufficient leakage pressure oil because the pressure at this port is low, and therefore sufficient lubrication is not ensured. There is a possibility that the lubrication state of both bearings 3, 3 may become unbalanced.

However, as mentioned above, the lubrication of the bearings 3 and 3 is
Such problems can be avoided by using a dedicated lubricating oil supply route without relying on this leaked pressure oil.

By the way, when the bearings 3, 3 are lubricated using a dedicated lubricant supply path as described above, leakage pressure oil reaching the inside of the bearings 3, 3 is caused by dust in the pressure oil coming into contact with the bearings. This alone is not desirable, but it is desirable to strengthen the independence so as to prevent leakage pressure oil from entering the lubricating oil supply path.

Therefore, in this embodiment, in order to ensure the independence of the lubricating oil supply path, leakage pressure oil recovery paths are provided near both ends of the spacer 25, which also serves as an oil path connecting member.

That is, an annular groove 91 formed on the outer surface 89 of the spacer 25
, 93 (positions corresponding to both ends of the spacer 250) are buttoned with annular grooves 127 and 129, respectively, on the headstock side sliding surface 95 that slides on the outer surface 89 of the spacer 25. Similarly, annular grooves 131 and 133 are carved at positions corresponding to annular grooves 127 and 129, respectively.

The headstock 1 includes an oil passage 1 having a drain port.
35 is formed, and this oil passage 135 communicates with the annular grooves 131 and 133.

In this way, an annular groove 127, 129° 131.13
3 are arranged, as mentioned above, the pressure oil leaking from the annular grooves 91, 93, 97, 99 and trying to reach the bearings 3, 3 through these sliding surfaces will reach there. On the way, this annular groove 127, 129, 131.133
The annular grooves 131 and 133
The oil is collected into a tank (not shown) through an oil passage 135 communicating with the oil.

Therefore, leakage pressure oil is prevented from entering the bearings 3, 3, and the bearing lubricating oil supply path can perform completely independent lubrication.

By the way, since the bearings are lubricated independently, the combination of bearings is not limited to ball (angular contact) bearings as shown in the example, but can also be used with other bearings,
For example, tapered, roller bearings can also be used to increase stiffness.

Here, the workpiece gripping action of the spindle device having such a configuration will be explained.

First, the workpiece W is placed on the main shaft 15 from the cover plate 69 side.
0 into the through hole 13, the center of the workpiece is positioned approximately at the center of the through hole 13, and pressure oil is supplied from the oil supply boat 101 to the pressure chamber 107 through the oil passages 103 and 105°109.
When supplied to It is pressed against the tapered hole portion 69 of the cover plate 65.

As a result, the gripping claws 75 and 77 tighten and fix the workpiece W by a wedge action.

Therefore, when a driving rotational force is applied to the V pulley 37, torque is transmitted to the gripping claw 77 side via the main shaft 15 and the cover plate 65, while on the other hand, the V pulley 37, the main shaft 15, Torque is transmitted via the pin 119 and the piston 47, and the workpiece W rotates integrally with the main shaft 15.

During this rotation, lubricating oil is supplied independently from the pressure oil to the bearing 3.3 that rotatably supports the main shaft 15 through the aforementioned lubricating oil supply path, ensuring appropriate and sufficient lubrication. .

When the workpiece W is to be removed after machining, pressure oil is passed through oil passages 111, 113, 117 to the pressure chamber 115.
If the collet 710 is fed into the inside, the distance between the taper hole 63 of the piston 47 and the taper hole 69 of the cover plate 65 is widened, and the gripping claws 75 and 77 on both sides of the collet 710 are released, and the workpiece is gripped by its own elastic force. Separate from the surface of W.

As a result, the workpiece W can be removed.

By the way, due to various causes such as power outages and emergency stops,
When the hydraulic pressure supply from a hydraulic pressure source such as a hydraulic pump stops or decreases, the pressure within the pressure chamber 107 of the cylinder tends to decrease.

One of the reasons why the pressure inside the pressure chamber 107 tends to decrease is the aforementioned leakage of pressure oil at the sliding surface between the spacer 25 and the headstock sliding surface 95. can.

When such a pressure drop occurs in the pressure chamber 107, the gripping claws 75, 77 expand due to the restoring force due to the elasticity of the collet foot itself, and the gripping state of the workpiece W is released.

When the gripping state of the workpiece W is released, the workpiece W becomes in a state where it can freely rotate, resulting in a dangerous situation.

Therefore, in this embodiment, in order to avoid such a dangerous situation, a spring 121 is interposed in the pressure chamber 101 so as to always urge the piston 47 in the direction of the collet 71 with its elastic force. There is.

The biasing force of the spring 121 is set to be greater than the restoring force of the collet foot itself.

In this way, if the spring 121 constantly applies an elastic force to the piston 47 by overcoming the restoring force of the collet 11 itself, the pressure chamber 1 may be accidentally damaged due to the reasons described above.
Even if the pressure inside collet 71 decreases, the collet 71
is prevented from restoring by the biasing force of the spring 121, and therefore does not release its grip on the workpiece W.

Therefore, unless a predetermined release operation is performed, the workpiece 71 will not accidentally shift to a freely rotating state, and no dangerous situation will occur due to the free rotation.

This spring may be provided in the pressure chamber 115 on the opposite side from the pressure chamber 107 by a so-called chuck method.

Naturally, the hydraulic tightening force when gripping the workpiece W is greater than the releasing force of the collet 71 due to the spring, and the spring remains bent.

By the way, when cutting the workpiece W while being gripped by such a spindle device, cutting oil may be used, and this cutting oil, chips, dust, etc. may damage the outer surface of the medium diameter portion 19 of the spindle 15 and the bearings. There is a risk that the oil may break the sealing state of the sealing member 33 that is oil-tight with the inner surface of the presser foot 5 and enter the bearing 3.

Therefore, in this embodiment, the front surface from the outer circumferential surface of the cover plate 65 to the outer circumference of the bearing presser 5 is covered with a substantially annular disk-shaped front cover 140, and this front cover 140 drains cutting oil and removes chips. , prevent the intrusion of dust, etc.

Furthermore, in order to prevent cutting oil from splashing onto the V-pulley 37, etc., it is preferable to provide a covering structure as shown in FIG. 2 on the V-pulley 37 side.

That is, a fixed cover 141 is provided on the outside of the outer end surface of the V pulley 37 in close proximity to this end surface, and a rotating cover 143 is provided on the outer end of the mallet body 53 of the piston 41 via a bolt 145. installed.

A cylindrical wall body 142 is protruded from the fixed cover 141, and the wall body 142 has a lid body 14 having a through hole in the center.
7 is attached with bolts 149.

The space surrounded by the wall 142, the lid 141, and the rotary cover 143 forms an oil reservoir chamber 151, and the space surrounded by the inner surface of the rotary cover 143 forms an oil reservoir chamber 153. .

A cutting oil supply port 15 is provided in both oil reservoir chambers 151 and 153.
7 and 155 are formed by opening a part of the wall body 142 and a part of the rotating cover 143, respectively.

In such a covering structure, the oil supply port 15
When coolant oil is supplied from 7, the oil flows into the oil reservoir chamber 151.
The oil is taken into the oil reservoir chamber 153 through the port 155 of the rotary cover 143 that rotates integrally with the main shaft 15, and comes into contact with the workpiece W.

In the past, oil appropriately overflowed from the inside of both oil reservoir chambers 151 and 153 through through holes formed in the center of the rotary cover 143 and the lid body 147.

According to such a covering structure, it is possible to avoid the risk of coolant oil splashing onto the V-pulley 37, and to supply a sufficient amount of coolant oil to the workpiece WFC, and also to prevent coolant oil from entering into the main shaft 15. can be reliably prevented.

Although the specific example illustrated above is the most preferable example for implementing the present invention, the present invention is not limited thereto in any way.
The present invention may be implemented with appropriate modifications and improvements without departing from the spirit thereof.

For example, the main shaft and the connecting body, the button, the piston main body, and the hammer body may be formed into an integral structure, and the main shaft drive is not limited to a V-pulley, but a gear or other rotating body may also be used.

As explained above, according to the present invention, in addition to supplying pressure oil as a drive source for chucking a work in the spindle device, there is a lubricant supply passage for lubricating the bearings, so that the bearings are lubricated. can be carried out adequately.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention, and FIG. 2 is a sectional view of essential parts showing another embodiment. 1... Headstock, 3... Ball bearing, 13... Through hole, 15... Main shaft,
37...V pulley, 45...Silling bore, 47...Piston, 61...Through hole, 63.69...Tapered hole part , 65...
... cover play), 75, 77 ... gripping claw section, 79.81 ... taper section, 103, 105
......Pressure oil passage, 121... Spring, 123, 125... Oil supply passage.

Claims (1)

[Scope of utility model registration request] a headstock, a main shaft having a through hole in the center, a pair of rolling bearings that are spaced apart from each other approximately in the center of the headstock and rotatably support the main shaft, and gripping claws at both ends. a collet slidably inserted into the through hole;
A ring-shaped cover plate is provided with a tapered hole corresponding to the taper of one of the gripping claws of the collet and is detachably fixed to one end of the main shaft, and a cylinder provided at the other end of the main shaft. and a small diameter portion that is oil-tightly fitted into the through hole, and is oil-tightly fitted into the cylinder portion, and has a through hole in the center and the other end of the collet formed at the end of the through hole. a piston having a tapered hole corresponding to the taper of the gripping claw; a rotating body for driving the main shaft such as a V-pulley or gear provided around the outer circumference of the cylinder; A spindle device with a built-in chuck, comprising: a pressure oil supply mechanism that supplies pressure oil to a cylinder portion; and a lubricant supply passage that supplies lubricant to the rolling bearing independently from the pressure oil supply mechanism. .