JPH0796185B2 - Constant pressure contact device for lens grinding wheel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to, for example, an edge end of a rough grinding lens before beveling a rough grinding lens held between lens axes of a slidable carriage body. The present invention relates to a lens constant pressure contact device for a grinding wheel grindstone used to determine the position of the bevel grindstone with respect to the V groove, that is, the coordinates in accordance with the size of the radius vector.

(Prior Art) There is a conventional ball slicing machine as shown in FIG. In this ball slicing machine, a rough grinding wheel 3 and a beveling wheel 4 are adjacently fixed to a rotary drive shaft 2 provided in a front portion of a main body 1.
In addition, the rotary drive shaft 2 is attached to the support portion 5 provided at the rear portion of the main body 1.
A support shaft 6 parallel to the above is held rotatably and movably in the axial direction, and a rear end portion of a carriage 7 is fixed to the support shaft 6. Moreover, a pair of lens shafts 8 and 9 arranged in parallel and coaxially with the support shaft 6 are rotatably held at the front end of the carriage 7. The lens shaft 9 is provided so that it can be moved back and forth with respect to the lens shaft 8, and the cloth lens L is fixed between the lens shafts 8 and 9 by a tightening operation of the lens shaft 9. Such lens shafts 8 and 9 are provided so that they can be synchronously driven by a pulse motor 10 for rotating the lens shaft in the carriage 7. A template 11 is removably attached to the end of the lens shaft 8.

Further, when the pulse motor 12 for lateral movement supported by a frame (not shown) is rotationally driven in the forward or reverse direction, the feed screw 13 is rotationally driven and the arm plate supported by the guide shaft 14 is driven.
15 moves back and forth in the direction in which the lens shafts 8 and 9 and the support shaft 6 extend. The end of the support shaft 6 is rotatably held by the arm plate 15, and the carriage 7 is driven forward and backward in the axial direction of the support shaft 6 via the arm plate 15 by the operation of the pulse motor 12. The arm plate 15 is provided with a die receiver 16 which is held so as to be able to move up and down, and a pulse motor 17 which drives the die receiver 16 to move up and down. The die receiver 16 is formed by attaching an abutting piece 16b to the upper portion of the die receiving body 16a so as to rotate up and down by a predetermined range around one end, and the abutting piece 16b is biased upward by a spring.

When processing the material lens L using such a ball slicing machine, the lens shafts 8 and 9 with the mold plate 11 abutting on the mold receiver 16 are processed.
And rotate the rough grinding wheel 3 as well as
When the mold holder 16 is lowered, the material lens L becomes the rough grinding wheel 3
Thus, the shape of the template 11 is roughly ground. In this roughly ground material lens L, the radius ρ _i from the center of rotation to the peripheral surface is different at each point in the circumferential direction, and at the same time, both surfaces are three-dimensional curved surfaces as shown in FIG. The edge of the edge changes in the axial direction of the lens axes 8 and 9. Therefore, when beveling is applied to the peripheral portion of the lens L that has been roughly ground as described above, the lateral movement amount of the carriage 7 must be controlled according to each moving radius ρ _i .
Ideal beveling cannot be applied to the peripheral edge of the lens L.

Therefore, in order to satisfy this point, as shown in FIG. 9, after the roughly ground lens L is moved onto the V groove 18 of the bevel grindstone 4, the die shaft 16 is vertically driven to move the lens shaft 8 , 9 is lowered from a predetermined height by a predetermined amount, and the lateral movement of the carriage 7 is repeatedly performed, so that the edge ends L _f , L _{b of the} lens L are
Is in contact with the inclined surfaces 18a, 18b of the V groove 18 in the Y direction (lens axis
(8, 9 axis direction) coordinates and edge thickness in advance at several radial points ρ
measured for each _i, which was set to determine the lateral movement amount during beveling corresponding to Kakudo径[rho _i is considered.
Incidentally, this concrete structure is disclosed in Japanese Patent Laid-Open No.
Same as −335672.

(Problems to be Solved by the Invention) In such a measurement, if the measurement position of the lens L is changed in the circumferential direction, the radius vector ρ _i also changes correspondingly, so that the edge L _{f of the} lens L changes. When the contact position of L _{b with} the inclined surfaces 18a, 18b is changed in the circumferential direction, the inclination angle θ of the carriage 7 at this time also changes.

However, since the abutting force of the edge ends L _f and L _b of the lens L on the inclined surfaces 18 a and 18 b utilizes the rotation moment due to the weight of the carriage 7, when the inclination angle θ of the carriage 7 changes,
Since the abutting force of the edge ends L _f , L _b of the lens L on the inclined surfaces 18 a, 18 b is increased, the inclined surfaces 18 a, 1 of the edge ends L _f , L _b of the lens L are increased.
The abutting force on 8b was not constant. Such an abutting force is generated even if the radius vector _i at the abutting point is changed by circumferentially moving the abutting positions of the edge ends L _f and L _b of the lens L on the inclined surfaces 18a and 18b. It is desirable for more accurate measurement that the pressure is sufficiently small and always constant due to the lens grinding pressure.

Then, this invention aims at providing the lens constant pressure contact device with respect to the grinding machine grindstone which satisfy | fills this request | requirement.

(Means for Solving the Problem) In order to achieve this object, the present invention provides a bevel grindstone mounted to the front part of a main body so as to be rotatable, and a forward / backward drive in a direction parallel to the rotation axis of the bevel grindstone. A garage base mounted on the main body and provided with a support portion, and a portion near the rear end portion is pivotally attached to the support portion via a support shaft parallel to the rotation axis and in front of the support shaft. A carriage main body having a center of gravity on the part side, and a pair of lens shafts provided on the carriage main body so that relative approach and separation can be adjusted coaxially in a direction parallel to the rotation axis and rotationally driven around the axis. An elastic member having one end attached to one of the rear end of the carriage main body and the carriage base, and the other end of the rear end of the carriage main body and the carriage base and the other end of the elastic member. Seeking a contact force adjusting means interposed, the radial rough grinding the lens abuts the grindstone between the lens axis corresponds to the axis rotation angle of the lens axis between,
At this radial position, the inclination angle of the carriage body when the rough grinding lens contacts the bevel grindstone is calculated, and the rotation lowering moment due to the weight of the carriage body that acts on the contact portion is calculated from the inclination angle. And a contact means for controlling the contact force adjusting means so that the difference between the rotation lowering moment and the rotation lowering preventing moment by the spring becomes constant, and a constant lens pressure contact to the grinding wheel grinder is provided. It is characterized by being used as a device.

(Operation) According to such a configuration, "the radius of contact between the rough grinding lens between the lens axes and the bevel grindstone is determined corresponding to the axis rotation angle of the lens axis, and the rough grinding is performed at this radius position. The inclination angle of the carriage main body when the lens contacts the bevel grindstone is calculated, and the rotation lowering moment due to the weight of the carriage main body acting on the contact portion is calculated from this inclination angle, and this rotation lowering moment is calculated. The control means drives the contact force adjusting means so that the difference from the rotation drop prevention measurement by the elastic member becomes constant. Thereby, even if the radius vector of the contact position changes, the contact force of the lens with the bevel grindstone becomes constant.

(Example) Hereinafter, an example of the present invention will be described with reference to FIGS.

FIG. 1 is a perspective view of a ball shaving machine including a lens constant pressure contact device for a grindstone according to the present invention. The same or similar parts as those shown in FIG. 8 are designated by the same reference numerals, The description is omitted. Further, the measurement of the lens edge position is carried out in the same manner as in JP-A-62-335672 previously filed by the applicant.

Therefore, the differences from these will be described in detail below.

A guide shaft 19 extending in a direction parallel to the rotary drive shaft 2 (rotary shaft) of the beveling grindstone 4 is attached to a rear portion of the main body 1 at a position not shown, and the guide shaft 19 has a carriage base.
20 is held so as to be movable back and forth in the longitudinal direction. The carriage base 20 is connected to the arm plate 15, and is driven to move back and forth integrally with the arm plate 15 in the axial direction of the guide shaft 19 by the pulse motor 12. Support portions 2 projecting upward are provided at both ends in the moving direction of the carriage base 20.
1, 21 are provided, and the carriage main body, that is, the portion near the rear end portions 7a, 7a of the carriage 7 is pivotally moved up and down by the support shafts 22, 22 coaxially arranged at the upper ends of the support portions 21, 21. Held in. The center of gravity G of the carriage 7 is located in front of the support shaft 22. A mold receiving sensor S is interposed between the mold receiving main body 16a of the mold receiving member 16 and the contact piece 16b. Since the same detector as that provided in the mold receiver of JP-A-62-335672 is used for this mold receiver sensor S in the same manner, its detailed description is omitted.

A contact force adjusting means 23 is attached to the rear end portion 7a of the carriage 7. The contact force adjusting means 23 includes a pulse motor 24 attached to the rear end portion 7a, a speed reducer 24a interlocking with the pulse motor 24, and a rotary shaft interlocking with the speed reducer 24a.
24b, a circular timing plate 25 mounted on the rotating shaft 24b, a spring mounting lever 26, and a rear end portion 7a.
Has a microswitch 27 attached to. The timing plate 25 is formed with a V-shaped notch 25a,
A micro switch is mounted on the peripheral surface of the timing plate 25.
The roller 27b at the tip of the actuator lever 27a of 27 is in contact. Then, when the roller 27a engages with the notch 25a,
The micro switch 26 is designed to be turned off.

A spring 28 is provided between the lower end of the lever 26 and the carriage base 20.

Further, the contact force adjusting means 23 is provided so as to be drive-controllable by a CPU 29 (central processing unit) as an arithmetic circuit (control means). This CPU 29 has a micro switch 26
, And the signal from the mold receiving sensor S is input.
Further, the CPU 29 controls the rotation time of the pulse motor 24 via the timer 30.

Such a CPU 29 calculates and stores the rotation angles of the lens shafts 8 and 9 from the drive control pulse signal of the pulse motor 10 during the rough grinding of the lens L.

Further, when measuring the position coordinates of the edge of the lens L that has been roughly ground, the CPU 29 sets the radius vector ρ _i that abuts the bevel grindstone 4 of the rough grinding lens L as the axial rotation angle of the lens shafts 8 and 9. Correspondingly, the tilt angle θ of the carriage 7 when the rough grinding lens L contacts the bevel grindstone 4 at this radius vector position is calculated from the obtained radius vector ρ _i and the known carriage arm length. Moreover, the CPU 29 determines the timer 30 based on the calculation result.
Determine the operating time and the energizing direction to the pulse motor,
The timer 30 controls the energization time and the energization direction of the pulse motor. At this time, the control of the energization time and the energization direction by the CPU 29 is started from the position where the roller 27b is engaged with the notch 25a and the micro switch 27 is OFF, and the tilt angle θ of the carriage 7 is applied. A rotation lowering moment due to the weight of the carriage 7 acting on the contact portion,
The rotation descent moment and the rotation descent prevention moment by the spring 28 are set to be constant.

As an example of this relationship, the rotation center of the carriage 7 is 0, the center of gravity of the carriage 7 is G, and the rotation center 0 is the axis line of the lens axis 0 ₁
Up to A, the length from the center of rotation 0 to the center of gravity G is C, and the point f where the spring force of the spring acts from the center of rotation 0
Up to B ₀ and the spring force acting on point f
And F _0, the weight at the center of gravity G as G _0, W ₀ the rotation drop moment acting on the contact point E and the axis 0 ₁ of the beveling grindstone of the lens by the rotation drop moment due to the weight G _0, Fig. 5 - This will be described with reference to FIG.

FIG. 5 shows a case where the carriage 7 is horizontal and the inclination angle thereof is zero. When the lens processing radius in this case is ρ ₀ , the relationship of A · W ₀ , C · G ₀ , B · F ₀ is A · W ₀ + C · G ₀ = B · F ₀ .

At this time, the pulse motor is controlled so that the lever is vertically downward.

Also, FIG. 6 is one in which machining radius vector [rho _i showed when a [rho ₀ is greater than [rho _1. In this case, as well as the length from the rotation center 0 and f ₁ that the spring force of the spring acts as B _1, if the spring force acting on the point f ₁ and F _1, the force relationship A・ W ₀ cos θ + C ・ G ₀ cas θ> B ₀・ F ₁ cos θ A ・ W ₀ cos θ + C ・ G ₀ cos θ = B ₁・ F ₁ cos θ '(B ₀ <B ₁ ) Therefore, in this case, the lever is rotated to the side away from the rotation center 0.

Further, FIG. 7 shows a case where the machining radius ρ _i is ρ _{2 which} is smaller than ρ ₀ . In this case, as well as the length from the rotation center 0 to the point f _2, which spring force of the spring acts and B _2, when the spring force acting on the point f ₂ and F _2, the force relationship A・ W ₀ cos θ + C ・ G ₀ cos θ <B ₀・ F ₂ cos θ A ・ W ₀ cos θ + C ・ G ₀ cos θ = B ₂・ F ₂ cos θ ′ (B ₀ > B ₂ ). Therefore, in this case, the lever is rotated toward the side closer to the rotation center 0.

Instead of calculating the inclination angle of the carriage by calculation, the first
As shown by the broken line in the figure, the rotary encoder for tilt angle detection
RF may be attached.

Further, the point of action of the spring force of the spring 28 on the carriage 7 is set by the rotating lever 26, but the present invention is not limited to this. For example, a spring relay member is attached to the rear end portion 7a of the carriage 7 so as to move forward and backward with respect to the front end portion of the carriage 7, and the spring 28 is attached to the spring mounting member.
The upper end portion of the carriage 7 may be held, and the spring mounting member may be controlled to move forward and backward with respect to the front end portion of the carriage 7 by a pulse motor, a cylinder or the like.

(Effects of the Invention) As described above, the present invention is such that a bevel grindstone is rotatably mounted on the front part of a main body, and is mounted on the main body so that it can be driven forward and backward in a direction parallel to the rotation axis of the bevel grindstone. And a carriage base provided with a support portion, and a portion near the rear end portion is pivotally attached to the support portion via a support shaft parallel to the rotation axis, and has a center of gravity on the front side of the support shaft. A carriage main body, a pair of lens shafts provided on the carriage main body so that relative approach and separation can be coaxially adjusted in a direction parallel to the rotation axis and rotationally driven around the axis, and a rear end of the carriage main body. Member and one end of the carriage base, and an interposition between the rear end of the carriage body, the other end of the carriage base, and the other end of the elastic member. Was done The contact force adjusting means and the radius of contact of the rough grinding lens between the lens shafts with the bevel grindstone are determined in correspondence with the axis rotation angle of the lens shaft, and the rough grinding lens is moved to the bevel grindstone at this radius position. The inclination angle of the carriage main body when it abuts on the carriage main body is calculated, and the rotation lowering moment due to the weight of the carriage main body acting on the contact portion is calculated from the inclination angle, and the rotation lowering moment and the elastic member are used. Since the control means for driving and controlling the contact force adjusting means is provided so that the difference from the rotation descent prevention moment becomes constant, when the edge of the roughly ground lens comes into contact with the bevel grindstone. Even if the contact position of the edge edge of the lens to the bevel grindstone is moved in the circumferential direction and the radius vector at the contact point changes, the contact force can be made sufficiently smaller than the processing pressure during lens grinding and always constant. Become. Further, this control can be used not only for contact measurement of the lens edge but also for adjusting the processing pressure of the lens grinding process.

Also, instead of the present invention, a method in which the rotation inhibiting moment of the carriage is used by changing the length of the spring is conceivable, but in this method, a spring having a large spring constant is used and the spring length is increased. A large torque spring length changing means for changing the height is required, and it is expected that the size of the device becomes large and energy is wasted. Further, the adjustment range of the blocking moment is small only by adjusting the spring length, and for example, it is impossible to adjust the contact force when measuring the lens edge thickness and the processing pressure during lens grinding with one mechanism. .

On the other hand, according to the present invention, since the action point (1) of the spring is changed, the adjustment device is simple, small-sized and energy-saving, and the adjustment range of the carriage rotation preventing moment can be widened. Thus, it can be used both for adjusting the contact force when measuring the lens edge thickness and for adjusting the processing pressure when grinding the lens.

[Brief description of drawings]

FIG. 1 is a perspective view of a ball shaving machine equipped with a lens constant pressure contact device for a grindstone according to the present invention. FIG. 2 is an explanatory view of a main part of the ball shaving machine shown in FIG. FIG. 3 is a right side view of FIG. FIG. 4 is a control circuit diagram of the lens constant pressure contact device shown in FIG. 5 to 7 are operation explanatory views of the lens constant pressure contact device shown in FIGS. 1 to 4. FIG. 8 is a perspective view showing an example of a ball slide machine. FIG. 9 is an operation explanatory view of the ball shaving machine shown in FIG. 1 ... Main body, 2 ... Rotation drive axis (rotation axis), 3 ... Rough grinding wheel, 4 ... Beveling wheel, 7 ... Carriage, 8,9 ... Lens axis, 11 ... Template, 16 ... … Mold receiver, 18 …… V groove, 20 …… Carriage base, 21,21 …… Supporting part, 22,22… Supporting shaft, 23 …… Abutting force adjusting means, 29 …… CPU (control means), L… …lens.

Front page continuation (72) Inventor Takahiro Watanabe 75-1 Hasunumacho, Itabashi-ku, Tokyo Within Tokyo Optical Co., Ltd. (72) Inventor Yasuo Suzuki 75-1 Hasunuma-cho, Itabashi-ku, Tokyo Tokyo Optical Co., Ltd. In the company

Claims (1)

[Claims] 1. A bevel grindstone that is rotatably mounted on the front part of a main body, and a gear that is mounted on the main body and is provided with a support part so that it can be driven back and forth in a direction parallel to the rotation axis of the bevel grindstone. A ridge base, a carriage body having a portion near the rear end portion pivotally attached to the support portion via a support shaft parallel to the rotation shaft, and a carriage main body having a center of gravity on the front side of the support shaft; Any of a pair of lens shafts provided on the carriage main body so as to be able to adjust relative approach / separation coaxially in different directions and to be rotationally driven about an axis; and a rear end portion of the carriage main body and the carriage base. An elastic member having one end mounted on one side, contact force adjusting means interposed between the other end of the carriage body and the other end of the carriage base, and the other end of the elastic member, Of the lens axis Rough grinding the lens between the lens axis corresponds to the rotation angle seeking radial contact with the grindstone,
At this radial position, the inclination angle of the carriage body when the rough grinding lens contacts the bevel grindstone is calculated, and the rotation lowering moment due to the weight of the carriage body that acts on the contact portion is calculated from the inclination angle. Constant pressure contact with the grinding wheel grinding wheel, the control means controlling the contact force adjusting means so that the difference between the rotation lowering moment and the rotation lowering prevention moment by the spring becomes constant. apparatus.