JPH03245015A - Rotary encoder - Google Patents

Abstract

PURPOSE:To make an encoder compact by arranging arc shaped patterns of leading phase contact points and delaying phase contact points on the same circumference of a code plate where signal leading-out terminals are provided, and providing a plurality of sliding contact points for sliding the patterns of the leading-phase and delaying-phase conduct points on a rotary shaft. CONSTITUTION:A ring shaped common signal pattern 2 is provided in the inside of a code plate 1. A pattern 3 for a leading-phase signal 3 and a pattern 4 for a delaying- phase signal on the two parts which are obtained by dividing the circumference are provided in the code plate 1. The patterns 2 - 4 are connected to terminals 12 - 14 for leading out the signals. Sliding contact points 5a and 5b are further attached to a rotor 7 which is rotated together with a rotary shaft 6 as a unitary body. The contact points 5a and 5b are located at the symmetrical positions with respect to the rotary shaft 6. Therefore, when the contact points 5a is located at the side of the pattern 3, the contact point 5b is located at the side of the pattern 4. When the contact point 5a is located at the side of the pattern 4, the contact point 5b is located at the side of the pattern 3. Therefore, when the rotary shaft 6 is rotated, the contact points 5a and 5b close and open the circuits with the pattern 2 together with patterns 3 and 4. Thus, the electric signals in two phases of the leading phase and the delaying phase are generated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an incremental rotary encoder having a sliding contact mechanism.

(Prior Art) With the spread of microcomputers, rotary encoders are being applied in a wide range of fields as human-powered devices for inputting rotational displacement information into microcomputers. Products with characteristics such as high resolution, long life, small size, and low cost are used depending on the field of application.

There are three generally known methods for detecting the amount of rotational displacement of a rotary encoder: an optical method, a magnetic method, and a sliding contact method. The optical type has a long life and can detect rotational displacement with high resolution, or requires a large space to combine a light emitting element and a light receiving element.

The magnetic type requires an amplifier, so it is large and expensive. The sliding contact type is small and inexpensive, but its resolution is low.

A typical sliding contact type incremental rotary encoder consists of a code plate for generating two-phase electrical signals, leading and lagging, and a sliding contact for contacting the code plate with pressure. It is configured. Depending on the configuration of the sliding contact and the code plate, there are two types of structure in which the electric signal is extracted from the terminal connected to the sliding contact and rotates the code plate, and another structure in which the sliding contact is rotated and the electric signal is output from the terminal connected to the coat plate. Structures for extracting signals are known.

(Problem to be solved by the invention) In a structure in which the coat plate is rotated simultaneously and the electric wires are taken out from the terminals of the sliding contacts, the same phase generation pattern (R) and the sliding contacts (A) and 7 are appropriately shifted. j1. By pressing i, a phase-leading contact and a slow-phase contact can be formed, so the coated plate has two phase generation patterns for both leading and slowing phases and a ring-shaped common pattern. Easy to fake. For this reason, sliding contact 4. In the '5 type incremental type rotary encoder, a structure in which the coat plate rotates at the same time is often used. Instead of making the pattern of the coat board easier, it becomes inductive tangent/slow tangent, lfi/jl: through tangent, ++7
, the three sliding contacts 1' (and the end r connected to these sliding contacts are required. The sliding contacts t and 1 have a structure in which they are pressed against the coated plate by the pressure of the spring, so the sliding contact If you try to make the terminal part integral with the contact by plastic insert molding, the terminal includes a sliding contact and a moving part, so special ingenuity and a lot of time are required for insert molding. It is.

The structure in which a sliding contact is rotated to extract an electrical signal from a terminal connected to a coated plate can be simplified because the sliding contact does not have the same function as a terminal. However, as shown in Figures 5 and 6, the code plate has two patterns of fast and slow phases in which the contacts are arranged in a circle, and a ring-shaped common contact, which is arranged twice on concentric circles. Therefore, in order to pull out the terminal from the inner button, a special device must be devised to pass it under the outer pattern. In addition, since there are many patterns on concentric circles, the structure of rotating the coating plate can be made more compact.

FIG. 7 is an example of a contact plate of a rotary switch.

This is equivalent to a coat plate in a rotary encoder, and it is mechanically integrated and electrically connected between the contacts for two circuits arranged in a circle and the common contact for two circuits inside. Independent sliding contacts 45a and 45b slide to open and close the circuit. The incremental type rotary encoder, which rotates a sliding contact and extracts electrical signals from a terminal connected to a coat plate, consists of a code plate with a pattern arranged around the circumference and a simple sliding contact. , its structure is very similar to that of a rotary switch.

Since a rotary switch has a structure with double patterns on concentric circles, the pattern of the code plate of a rotary encoder with a structure that rotates sliding contacts is simplified and the triple pattern on concentric circles is changed to a double pattern. If this is possible, the code plate can be made smaller and its outer size can be reduced. Furthermore, if the outer pattern is divided, the inner pattern can be drawn out from the gap, so there is no need for special measures to draw out each terminal.

If parts common to the rotary switch can be used, it is possible to create a rotary encoder with the same external shape as the rotary switch, which reduces parts and mold costs, making it possible to provide a low-cost rotary encoder.

The present invention simplifies the pattern of the code plate of an incremental type rotary encoder having a structure in which the coat plate is fixed, and (a) miniaturizes the coat plate to reduce the external size of the rotary encoder.

(b) Improve the resolution of rotational displacement detection in applications where the external size is not reduced. (C) Simplify the method of manufacturing the code plate. (d) The purpose is to standardize rotary switches and parts, to make rotary encoders and rotary switches a series product with the same external shape, and at the same time to reduce the cost of parts and molds.

(Means for solving the problem) An incremental type rotary encoder has a structure in which a sliding contact is rotated and an electrical signal is extracted from a terminal connected to the code plate.The code plate of the incremental type rotary encoder is divided into arcs for use in phase advance signals. The pattern and the slow phase signal pattern are arranged on one circumference. The common signal pattern is ring-shaped or has a length equal to or longer than the sum of the arcs of the divided leading phase signal pattern and the divided phase slow signal pattern. The leading and slow signal patterns and the common signal pattern lined up on one circumference are double lined up on a concentric circle, and the sliding contact attached to the rotating shaft at the center of the concentric circle overlaps. The structure is such that it generates electrical signals while sliding between the patterns. Two or more sliding contacts are provided on the rotating shaft, and the positional relationship between the two is such that when one sliding contact slides on the phase lead (or slow) signal pattern, the other sliding contact !
One of the signals 1 is made to slide over the pattern 1 for the slow (or fast) signal. The number of pulses emitted during one rotation of the rotating shaft is set to an integer (12 in FIG. 1) equal to the number of sliding contacts J1 length (2 in the figure).

(Function) When the rotating shafts of the rotary encoder configured as described above rotate simultaneously, looking at only one sliding contact, the sliding contact,
The ton slides on the top of the phase-advance signal pattern or the top of the slow-phase signal pattern, but at the same time, one of the other mechanically interlocked sliding contacts connects with the first sliding contact. On the contrary, it slides on -1 of the pattern for the slow signal and slides on the pattern for the fast signal, so the pattern for the fast signal and the pattern for the slow signal each slide without interruption. It is slidable by a dynamic contact, IIX, and can generate two-phase electrical signals.

The coat plate of the incremental type rotary encoder according to the present invention is more concentric than the coat plate of the conventional incremental type rotary encoder, which has a structure in which the sliding contact is rotated and the electric signal J is taken out from the terminal connected to the coat plate.
Since the number of I] is small, the board can be made smaller, and the outer shape of the row reencoder can also be made smaller. In addition, if you place the J (communication signal pattern) inside the phase signal pattern and the slow phase (ci signal pattern), you can pull out the terminal of the communication signal pattern from between the phase leading signal pattern and the slow phase (ci signal pattern). There is no need for any special device to draw out each terminal from each pattern.In addition, the pattern for Soshin 5 and the pattern for No. 7] The structure in which the sliding contact provided on one rotating shaft slides is very similar to that of a rotary switch, so parts of the rotary switch can be shared.

In conventional horizontal rotary encoders that rotate a coated plate, the sliding contacts and terminals are integrated, so special ingenuity is required to make the terminals, including the moving parts called sliding contacts, using plastic insert molding. A process was necessary. However, in the code plate according to the present invention, the coat plate and the terminal are integrated and do not include any movable parts, so insert molding is easy. The coat plate of an incremental type rotary encoder with a structure in which the code plate rotates, which is commonly used in the past, and the code plate according to the present invention have the same double concentric pattern, so if the resolution is the same, the diameter of the pattern is the same. Can be made to any size.

(Embodiment) FIG. 1 is an exploded perspective view of a code plate 1 according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view of a rotary encoder according to the same embodiment, in which 12 pulses are generated during one revolution of the rotating shaft. The code plate 1 has a pattern of double concentric circles, on the inside there is a ring-shaped common signal pattern 2, and on the outside there is a phase advance signal pattern 3 on one of the arcs that bisect the circumference. The other one of the circular arcs has a pattern 4 for a slow signal. Each pattern has terminals 12, 13, and 1 for signal extraction.
Connected to 4. Sliding contact? , t5a and 5b are attached to a rotor 7 that rotates integrally with a rotating shaft 6. The sliding contacts 5a and 5b drawn in the drawing of the coated plate 1 in FIG. 1 are the sliding contacts attached to the rotor 7, or the sliding contacts 5a and 5b when sliding on the coated plate.
The positional relationship between the double concentric circle pattern and the sliding contacts 5a and 5b changes as the rotor 7 rotates. The meanings of the sliding contacts written in the drawings of other code plates are also the same as in FIG.

Since the sliding contacts 5a and 5b are located at symmetrical positions with respect to the rotation axis, when the sliding contact 5a is on the side of the pattern 3 for the advanced phase signal, the sliding contact 5b is on the side of the pattern 4 for the slow phase signal. Therefore, when the sliding contact 5a is on the side of the pattern 4 for a slow signal, the sliding contact 5b is on the side of the pattern 3 for a fast signal. For this reason, regardless of the rotational position of the rotating shaft 6, both the pattern 3 for a phase-leading signal and the pattern 4 for a slow-phase signal are slid by one of the sliding contacts 5a and 5b. By rotating the rotating shaft 6, the sliding contacts 5a and 5
b is pattern 3 for leading phase signals and pattern 4 for slowing signals
By closing and opening the circuit between the circuit and Kyodo CJ pattern 2, two-phase electrical signals of leading and lagging phases are generated.

FIG. 3 shows how the leading phase and slow phase open and close with respect to the rotation angle at this time. FIG. 7 shows an example of a contact plate of a two-circuit rotary switch, and two sliding contacts 45a and 45b are provided. Since the pattern 3 for the advanced phase signal and the pattern 4 for the delayed phase signal are located on the same circle 1, it can be seen that the structure is very similar to the contact plate of the rotary switch shown in FIG.

FIG. 4 shows a coated plate 2I of another embodiment.

Leading signal pattern 23 (or lagging signal pattern 24
) is one-third or more of the circumference, and the slow-phase signal pattern 24 (or earth-phase signal pattern 23) is also arranged at one-third or more of the circumference. . The remaining portion may include a portion having neither a leading nor a slow phase pattern. The number of pulses generated during one rotation of the rotating shaft is an integral multiple (1 in Figure 4) of the number of sliding contacts (3 in Figure 4).
2).

There are three sliding contacts 2 at 120 degree intervals around the rotation axis.
Since 5a, 25b, and 25c are arranged, the sliding contacts are always sliding on both of the two patterns of phase advance and phase delay. Even if the rotation axis is in the position 25
Both the phase-leading signal pattern 23 and the phase-lag signal pattern 24 are slid by one of the sliding contacts a, 25b, and 25c, and it is possible to obtain two-phase electrical signals, leading and slowing. It is sufficient that there is enough space for the sliding contact to pass through in the area where there is no wing turn in either phase leading or slowing phase.
It can be seen that the rotary encoder can be made even smaller since no space is required to hold the pattern. Figure 7 shows an example of a contact plate for a two-circuit rotary switch, but since the three sliding contacts of a three-circuit rotary switch are arranged at 120 degree intervals around the rotation axis, this It can be seen that the code plate 21 of the embodiment has a structure very similar to the contact plate of a rotary switch.

(Effects of the Invention) The resolution of the rotary encoder is determined by the innermost leading or lagging signal pattern.

The code plate of the conventional rotary encoder shown in FIGS. 5 and 6 has a triple circular pattern, but the coat plate of the rotary encoder of the embodiment explained using FIGS. 1 and 4 has a double circular pattern, so it has a circular pattern. The code board can be made smaller by the number of patterns. If the code plate is made smaller, the external size of the rotary encoder can also be made smaller.

Furthermore, in order to obtain the same resolution, using the code plates shown in FIGS. 1 and 4 can be made smaller than the rotary encoder using the code plates shown in FIGS. 5 and 6.

For example, if the width of the pattern is 1.5mff1, as shown in Figure 1.
The diameter of the code plate pattern in Fig. 4 is 3□ more than that of the code plate pattern in Fig. 5, and 6ff111 larger than that of the code plate in Fig. 6.
It can also be made smaller. If the diameter of the code plate pattern of the embodiment shown in FIGS. 1 and 4 is 6ffIII+,
The conventional code plate pattern shown in Figure 5 is 9m+n.

The fact that the conventional code plate pattern shown in FIG. 6 has a size of 12+n+++ shows that the present invention is effective in reducing the size of the rotary encoder.

Further, referring to the above example, if the diameter of the pattern of the code plate of the embodiment shown in FIGS. 1 and 4 is set to 12M, which is the same as the diameter of the pattern of the conventional code plate of FIG. Since it can be doubled (-12 agony = 6ms+),
The resolution can also be doubled. From this, it can be seen that the resolution of rotational position detection can be improved in applications where the external size is not reduced.

As can be seen from the code plates of the embodiments shown in FIGS. 1 and 4, in the code plate according to the present invention, the terminals of the common signal pattern can be drawn out from between the phase-leading signal pattern and the phase-lag signal pattern. No special device is required to draw out each terminal from each pattern. Since the code plate and terminal do not contain any moving parts, insert molding is also simple.

Providing sliding contacts at positions equally divided by integers around the rotation axis of the rotary encoder means that a single contact +
[K board] This is a widely used method for rotary switches that have multiple circuits on the second side. In addition, since both the contact plate of the rotary switch and the coated plate according to the present invention have a double concentric circle pattern, if the contact plate 7 (, ``j&'' of the rotary switch is replaced with the contact plate according to the present invention, the outer shape is the same as that of the rotary switch. A rotary encoder can be easily manufactured, and a rotary switch and a rotary encoder can be made into a series product with the same external shape.

Sliding contacts and contacts necessary to configure a rotary encoder
Since you can make a rotary encoder by sharing the rotary switch parts without having to make new parts for the rotor, [[]j+musuke, and haunong, etc., you can save on mold costs, etc., and the parts can also be mass-produced. I hope it will be cheaper.

[Brief explanation of drawings]

FIG. 1 is a coated plate according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of a rotary encoder according to the same embodiment, FIG. 3 is a diagram showing how the contacts open and close with respect to the rotation angle of the same embodiment, and FIG. 4 is another example. Figures 5 and 6 show the coat plate of a conventional incremental rotary encoder with rotating sliding contacts, and Figure 7 shows the contact plate of a rotary inch. 2, 22... Pattern for common signal, 3, 23... Pattern for advanced phase signal, 4, 24... -... Slow phase (pattern for No. 6, 5a, 5b, 25a, 25b, 25c sliding contact.

Claims (1)

[Claims] In an incremental type rotary encoder that converts the amount of rotational displacement of the rotating shaft into two-phase electrical signals, leading and slowing, using a sliding contact mechanism, an arc-shaped leading phase contact is attached to a code plate equipped with a terminal for extracting the signal. The pattern and the pattern of the slow contact are arranged on the same circumference, and the rotating shaft has a plurality of sliding contacts to generate electrical signals while sliding the pattern of the fast phase contact and the pattern of the slow contact. An incremental type rotary encoder characterized by being equipped with contacts.