JP5123677B2 - Lens processing equipment - Google Patents

Description

  The present invention relates to a lens processing apparatus that performs cutting and polishing of a surface of a lens material while pressing the surface of a lens material to be processed against a processing surface of a rotating lens processing tool and subjecting the surface to rotation. More specifically, fine adjustment of the pressing force that presses the lens material against the lens processing tool during lens processing can be performed with high precision, and the lens can be moved following the vibration during lens processing. The present invention also relates to a lens holding / pressurizing mechanism of a lens processing apparatus in which a lens is vacuum-sucked and can be sucked and held by a lens holder.

  A lens processing apparatus having a structure shown in FIG. 2 is known. In the lens processing apparatus 100 shown in this figure, a hollow spindle 104 is coaxially attached to a hollow portion of a hollow lens support shaft 102 via a bearing 103 in a rotatable state. A lens holder 105 is fixed downward at the lower end of the hollow spindle 104 in a coaxial state.

  A lens processing tool 106 is disposed below the lens holder 105 in an upward state. The lens processing tool 106 includes a curved processing surface 106a, and is rotationally driven by a driving source (not shown) around the central axis 106b. The lens processing tool 106 is swung, for example, left and right by a swing mechanism (not shown) around the intersection of the center axis 106b of the lens processing tool 106 and the center axis 101 of the upper spindle. During processing, the center axis 106b And 101 can be changed.

  At the time of processing, the surface of the lens material 111 held by the lens holder 105 is pressed against the processing surface 106 a of the rotating lens processing tool 106 by the lens support shaft 102. Since the hollow spindle 104 to which the lens holder 105 is attached is supported by the lens support shaft 102 so as to be rotatable, the hollow spindle 104 rotates dependently around the central axis 101 as the lens processing tool 106 rotates. In this way, the lens surface is obtained by a combination of the rotational movement of the lens processing tool 106 around the central axis 101, the dependent rotational movement of the lens material 110 around the central axis 101, and the swinging movement of the lens processing tool 106. Cutting, polishing, etc. are performed.

Here, the lens support shaft 102 is supported by a bearing 110 so as to be slidable in the vertical direction. The processing pressure at the time of lens processing is obtained by pressurizing means (not shown) such as a spring and a cylinder provided on the upper portion of the lens support shaft 102. The processing pressure by the pressing means is transmitted to the lens holder 105 via the lens support shaft 102, the bearing 103, and the hollow spindle 104, and the lens material 111 held between the lens holder 105 and the lens processing tool 106. Is pressed against the processing surface 106a. The pressurizing means is known as described in Patent Document 1, for example.
JP 2007-15074 A

  The lens material holding mechanism and the pressure mechanism in the conventional lens processing apparatus have the following problems. First, a lens support shaft 102, a bearing 103, and a hollow spindle 104 are disposed between the pressure unit and the lens holder 105. Therefore, since the weight of the lens support shaft 102 is applied in the pressing direction, it is difficult to apply a minute processing pressure. In order to be able to apply a minute processing pressure, it is necessary to reduce the weight of the pressure mechanism including the lens support shaft 102. For example, it is conceivable to reduce the weight by making the lens support shaft 102 a thin and small-diameter pipe. However, this is not preferable because the mechanical strength and rigidity of the lens support shaft 102 are insufficient and the processing accuracy is deteriorated.

  Conventionally, the weight of the lens support shaft 102 always acts on the lens holder 105 during lens processing. Therefore, when the processing pressure changes instantaneously due to vibration or the like, the lens holder 105 moves up and down following the instantaneous change in processing pressure due to the inertial force of the lens support shaft 102. Can not do it. As a result, an excessive force may act on the lens material being processed to cause a problem such as damage or deformation of the lens.

  Further, conventionally, in order to suck and hold the lens material 111 to be processed on the lens holding surface of the lens holder 105, a vacuum suction passage is arranged from the lens holder 105 to the inside of the hollow spindle 104 and the lens support shaft 102. It extends via the vacuum tube 112. During lens processing, the hollow spindle 104 is rotatably held with respect to the lens support shaft 102. Therefore, when the lens material 111 to be processed is sucked and held on the lens holding surface, the end of the vacuum tube 112 is pressed against the end of the hollow spindle 104 via the O-ring 113 to form an airtight vacuum suction passage. . At the time of lens processing, the vacuum tube 112 is separated from the hollow spindle 104 so that the hollow spindle 104 can smoothly rotate following the lens processing tool 106. For this reason, the lens material 111 cannot be sucked and held on the lens holding surface of the lens holder 105 during lens processing. In order to realize high-precision lens processing, it may be desirable to suck and hold the lens material being processed on the lens holding surface, but in the past, the lens material cannot be sucked and held on the lens processing surface during processing. There is inconvenience.

  An object of the present invention is to propose a lens processing apparatus capable of solving such conventional problems.

In order to solve the above-described problems, the present invention provides a lens processing apparatus that performs cutting, polishing, and the like of the lens material while pressing the lens material against the processing surface of the rotating lens processing tool and rotating the lens material.
A lens support shaft that can be raised and lowered relative to the lens processing tool;
An outer cylinder extending downward in a coaxial state from the lower end surface of the lens support shaft;
An inner cylinder arranged coaxially inside the outer cylinder and slidable in the direction of the central axis of the lens support shaft;
A spindle arranged coaxially inside the inner cylinder and rotatable about the central axis;
A lens holder attached coaxially to the lower end of the spindle and rotatable about the central axis;
A spring base in which an inner peripheral side portion is fixed to a lower end portion of the inner cylinder, and an outer peripheral side portion is attached to the lower end portion of the outer cylinder so as to be movable upward by a predetermined amount along the central axis. When,
A pressure nut screwed into the outer peripheral surface portion of the upper end side of the outer cylinder;
A pressure spring is disposed between the pressure nut and the spring base so as to surround the outer cylinder.

  In the lens processing apparatus of the present invention, an outer cylinder extending coaxially from the lower end of the lens support shaft is provided, a spindle is rotatably arranged inside the outer cylinder so as to be slidable in the vertical direction, and is arranged outside the outer cylinder. The lens processing pressure is applied to the spindle by the arranged pressure spring. Further, the lens processing pressure can be changed by adjusting the compression state of the pressure spring by turning the pressure nut.

  As described above, in the present invention, since the lens processing pressure is not affected by the weight of the lens support shaft, a minute processing pressure can be applied to the lens holder, and a fine processing pressure can be finely adjusted. Further, since the inertial force due to the lens support shaft does not act on the lens holder, the lens holder can move up and down following the change in processing pressure due to vibration during lens processing. Furthermore, since it is not necessary to reduce the weight of the lens support shaft, the lens support shaft can be provided with sufficient mechanical strength and rigidity, and lens processing accuracy can be maintained.

Next, in the lens processing apparatus of the present invention,
The spindle is a hollow spindle;
From the lens holding surface of the lens holder, through the hollow portion of the hollow spindle, a vacuum suction path communicating with the hollow portion of the outer cylinder is formed,
A sealing mechanism that supports the hollow spindle in a rotatable and vertically slidable state is disposed at a communicating portion between the hollow portion of the hollow spindle and the hollow portion of the outer cylinder. It is said.

  The lens to be processed can be sucked and held on the lens holding surface of the lens holder through the vacuum suction path. The hollow spindle can be rotated and slid up and down by the sealing mechanism. Therefore, the lens can be processed in a state where the lens is held by suction on the lens holding surface.

  Embodiments of a lens processing apparatus to which the present invention is applied will be described below with reference to the drawings.

  FIG. 1 is a schematic configuration diagram showing a main part of the lens processing apparatus according to the present embodiment, in which the right half is shown in cross section. The basic configuration of the lens processing apparatus 1 is the same as that of the conventional one, and has a lens support shaft 3 that can be moved up and down along the vertical axis 2. A hollow spindle 4 is connected to the lens support shaft 3 with respect to the vertical axis 2. It is attached so that it can rotate around and slide in the direction (vertical direction) of the vertical axis 2. A lens holder 5 is fixed downward at the lower end of the hollow spindle 4 in a coaxial state. The downward surface of the lens holder 5 is a curved lens holding surface 5a, on which the lens material 6 to be processed can be sucked and held. The lens processing tool 7 faces the lens holding surface 5a from below. The lens material 6 is conveyed to a position directly above the lens processing surface 7a of the lens processing tool 7 while being sucked and held by the lens holder 5, and the lens holding surface 5a of the lens processing tool and the lens of the lens processing tool 7 are conveyed. The lens is sandwiched by a predetermined processing pressure between the processing surfaces 7a, and in this state, the processing shaft 7b of the lens processing tool 7 rotates and swings, whereby the lens surface of the lens material 6 is polished and ground.

  The lens processing apparatus 1 includes a lens pressing mechanism for applying a processing pressure to the lens material 6. The structure of the lens pressurizing mechanism will be described. From the lower end surface 3a of the lens support shaft 3, a support shaft cylindrical portion 3b extending downward in a coaxial state is formed. A set tube 11 having a circular cross section is fixed so as to surround the support shaft cylindrical portion 3b in a coaxial state. An outer tube 12 having a circular cross section is fixed coaxially inside the support shaft cylindrical portion 3b. The upper end portion 12 a of the outer tube 12 is fitted and fixed to the lower end opening of the lens support shaft 3. These support shaft cylindrical part 3b, set tube 11 and outer tube 12 constitute an outer cylinder.

  The set tube 11 and the outer tube 12 extend below the lower end of the support shaft cylindrical portion 3b, and these lower end portions 11b and 12b are connected and fixed to each other. A pressure nut 13 is screwed into the upper end portion of the outer peripheral surface of the set tube 11. Further, a pressure spring 14 made of a coil spring is disposed in a state surrounding the outer peripheral surface of the set tube 11, and the upper end of the pressure spring 14 is pressed against the pressure nut 13 from below.

  Next, an inner tube 15 (inner cylinder) having a circular cross section is arranged inside the outer tube 12 so as to be slidable in the vertical direction in a coaxial state. Inside the inner tube 15, the hollow spindle 4 is coaxially supported in a rotatable state via ball bearings 16, 17 disposed at positions separated in the direction of the vertical axis 2 (up and down). A spring base 18 is fixed to the lower end of the inner tube 15.

  The spring base 18 includes a disc-shaped portion 18a in which a central hole is formed, an annular portion 18b projecting upward from the inner peripheral edge of the disc-shaped portion 18a, and a circle projecting upward from the outer peripheral edge of the disc-shaped portion 18a. And an annular portion 18c. The inner annular portion 18b is screwed and fixed to the inner peripheral surface portion of the lower end opening of the inner tube 15 from below, and the space between the annular portion 18b and the hollow spindle 4 is rotatable by a seal ring. Blocked. A stopper mounting hole 18d extending in the radial direction is formed in the outer annular portion 18c. A stopper 19 is inserted and fixed horizontally into the stopper mounting hole 18d from the outside. The inner end portion of the stopper 19 is inserted into an engaging groove 12c having a fixed length in the vertical direction formed in the lower end portion of the outer tube 12 so as to be slidable in the vertical direction. An annular seat surface 18e on which the lower end of the pressure spring 14 is seated is formed at the upper end portion of the outer annular portion 18c.

  Next, the lens processing device 1 includes a vacuum suction path for vacuum suction of the lens material 6 on the lens holding surface 5 a of the lens holder 5. This vacuum suction path is connected to a vacuum generation mechanism (not shown) via an air tube 21 inserted into the lens support shaft 3 from the lens holding surface 5a via the hollow portion 4a of the hollow spindle 4.

  Here, the upper end 4b of the hollow spindle 4 is surrounded by the upper end 12a of the outer tube 12 in a coaxial state. An O-ring 22 is sandwiched between the outer peripheral surface portion of the upper end portion 4b and the inner peripheral surface portion of the upper end portion 12a. Further, an annular protrusion 12d protruding inward is formed on the upper end portion 12a of the outer tube 12, and an annular step surface 12e is formed on the upper side thereof, and the upper and lower portions are vertically The O-ring 22 is movable. By this sealing mechanism, the hollow spindle 4 is held in a state where it can rotate and slide up and down.

  A small-diameter connecting tube portion 12f protrudes upward from the upper end of the upper end portion 12a of the outer tube 12. The air tube 21 is inserted and fixed from above to the connecting pipe portion 12f as necessary. By arranging the air tube 21, a vacuum suction path is formed.

  In the lens processing apparatus 1 configured as described above, the lens pressing mechanism including the set tube 11, the outer tube 12, the pressure nut 13, and the pressing spring 14 is provided on the support shaft cylindrical portion 3 b of the lens support shaft 3 from the lower side. It is attached. Next, a spindle unit composed of the inner tube 15, the spring base 18, the hollow spindle 4, and the ball bearings 16 and 17 is assembled, the spindle unit is inserted into the lens pressing mechanism from below, and the stopper 19 is engaged with the engagement groove of the outer tube 12. Insert it into 12c and fix it so that the spindle unit does not fall off and rotate.

  The inner tube 15 can slide up and down within the outer tube 12 without resistance. Moreover, the amount of contraction of the pressure spring 14 can be adjusted by turning the pressure nut 13 attached to the outer periphery of the set tube 11 and adjusting the position up and down. The pressure spring 14 presses the spindle unit downward via the spring base 18. Accordingly, the pressure spring 14 can generate a processing pressure that presses the lens holder 5 and the lens material 6 against the lens processing tool 7, and the pressure pressure can be adjusted by turning the pressure nut 13.

  Further, when it is necessary to hold the lens by vacuum suction, the air tube 21 is inserted into the connecting tube portion 12f at the upper end of the outer tube 12 to form the vacuum suction path shown in FIG. What is necessary is just to vacuum-suck by a mechanism.

(Operational effects of the embodiment)
According to the lens processing apparatus 1 having this configuration, the processing pressure during processing can be finely adjusted, deformation due to processing pressure of a small diameter lens or a thin lens can be prevented, and the lens material 6 and the lens processing tool 7 can be prevented from being deformed. Deformation due to heat generated from excessive friction can also be prevented.

  In addition, since a small and lightweight spindle unit can be configured, the inertial force acting on the lens holder 5 can be reduced. As a result, the lens holder 5 can be moved up and down instantaneously against an impact caused by vibration or the like. Therefore, since the lens material 6 and the lens processing tool 7 can always be held in close contact with each other, uneven wear and damage of the lens processing tool 7 are eliminated, and processing accuracy and processing quality are improved.

  Furthermore, since the weight of the lens support shaft 3 does not act as a processing pressure, there is no restriction on the weight of the lens support shaft 3. Therefore, it is possible to attach a lens support shaft having high mechanical strength and rigidity, which is advantageous for improving the accuracy of lens processing.

  Furthermore, in the conventional structure, the lens support shaft slides up and down, and when the lens processing accuracy changes due to wear of the lens support shaft or bearing, the repair must be done by a professional engineer. It took a lot of time and money. According to this example, it is only necessary to replace the outer tube 12 and the inner tube 15, so that repair can be performed by the user, and repair time and repair costs can be reduced.

  In addition, since the lens material 6 can be vacuum-sucked into the lens holder 5 during lens processing, an unstable lens shape can be processed with high accuracy. Further, it is not necessary to use a machined part such as a conventional vacuum tube for vacuum suction, and a mechanism for moving the vacuum tube up and down is unnecessary. Since the air tube 21 can use inexpensive and available parts, it is easy for the user to procure parts, and replacement work and the like can be performed without requiring a special technique.

It is a schematic block diagram of the lens processing apparatus to which this invention is applied. It is a schematic block diagram of the conventional lens processing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lens processing apparatus 2 Vertical axis 3 Lens support shaft 3a Lower end surface 3b Support shaft cylindrical part 4 Hollow spindle 4a Hollow part 4b Upper end part 5 Lens holder 5a Lens holding surface 6 Lens material 7 Lens processing tool 7a Lens processing surface 7b Processing axis 11 set tube 12 outer tube 12a upper end portion 12b lower end portion 12c engagement groove 12d annular projection 12e stepped surface 12f connecting pipe portion 13 pressure nut 14 pressure spring 15 inner tube 16, 17 ball bearing 18 spring base 18a disk-shaped portion 18b Annular part 18c Annular part 18d Stopper mounting hole 18e Seat 19 Stopper 21 Air tube 22 O-ring

Claims (3)

In a lens processing apparatus that performs cutting, polishing, etc. of the lens material while pressing the lens material against the processing surface of the rotating lens processing tool,
A lens support shaft that can be moved up and down relative to the lens processing tool;
An outer cylinder extending downward in a coaxial state from the lower end surface of the lens support shaft;
An inner cylinder arranged coaxially inside the outer cylinder and slidable in the direction of the central axis of the lens support shaft;
A spindle arranged coaxially inside the inner cylinder and rotatable about the central axis;
A lens holder attached coaxially to the lower end of the spindle and rotatable about the central axis;
A spring base in which an inner peripheral side portion is fixed to a lower end portion of the inner cylinder, and an outer peripheral side portion is attached to the lower end portion of the outer cylinder so as to be movable upward by a predetermined amount along the central axis. When,
A pressure nut screwed into the outer peripheral surface portion of the upper end side of the outer cylinder;
A lens processing apparatus, comprising: a pressure spring disposed between the pressure nut and the spring base so as to surround the outer cylinder. The lens processing apparatus according to claim 1,
The outer cylinder includes a support shaft cylindrical portion that extends downward in a coaxial state from the lower end surface of the lens support shaft, a set tube that surrounds the support shaft cylindrical portion in a coaxial state, and a coaxial inside the support shaft cylindrical portion. It consists of an outer tube placed in a state,
The set tube and the outer tube extend below the lower end of the support shaft cylindrical portion, and these lower end portions are connected and fixed to each other.
A lens pressing mechanism including the set tube, the outer tube, and a pressure nut and a pressing spring attached to the outer peripheral surface of the outer tube is attached to the lower end surface of the lens support shaft from below. And
A spindle unit including the inner tube, the spring base, and the spindle is inserted into the lens pressure mechanism attached to the lens support shaft from below.
A stopper is inserted into the stopper mounting hole formed in the spring base from the outer peripheral side, and the inner end portion of the stopper can be slid vertically in an engaging groove having a fixed length in the vertical direction formed in the outer tube. The lens processing apparatus is fixed to the lens pressing mechanism so that the spindle unit does not fall off and rotate when inserted in a stable state . The lens processing apparatus according to claim 1 or 2,
The spindle is a hollow spindle;
From the lens holding surface of the lens holder, through the hollow portion of the hollow spindle, a vacuum suction path communicating with the hollow portion of the outer cylinder is formed,
A sealing mechanism that supports the hollow spindle in a rotatable and vertically slidable state is disposed at a communicating portion between the hollow portion of the hollow spindle and the hollow portion of the outer cylinder. Lens processing equipment.

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