JP7280761B2 - Rotational speed measuring device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a rotational speed measuring device suitable for use in measuring the rotational speed of a rotary shaft of a transmission.

A rotation speed sensor is installed in a mechanism that needs to grasp the rotation speed of a rotating shaft. Rotational speed sensors include, for example, a configuration in which an annular rotating body that rotates integrally with a rotating shaft is provided with projections and depressions, and a sensor such as a proximity switch reads the projections and depressions to detect the rotational state.

In the case of a power transmission mechanism with two sprockets and a chain wound around them, a large number of teeth that mesh with the chain are formed on the outer periphery of the sprockets. A technique for detecting a state has been proposed (Patent Document 1).

Japanese Utility Model Laid-Open No. 5-89312

However, when the proximity switch reads the unevenness of the teeth of the sprocket as in the above-described prior art, there is a risk that the reading accuracy will decrease and it will be difficult to secure a space for arranging the proximity switch.

When using a proximity switch to read the unevenness of a sprocket tooth, the proximity switch is arranged on the side of the sprocket tooth, and the detection direction of the proximity switch is directed in a direction parallel to the rotation axis of the sprocket. There is a configuration in which a proximity switch is arranged at the center of the sprocket and the detection direction of the proximity switch is directed toward the center of rotation of the sprocket.

In the former case, since the teeth of the sprocket are corrugated, the length of the pulse changes depending on which radial position on the side surface of the tooth is measured, and detection accuracy tends to decrease. Also, since it is difficult to detect the teeth of the sprocket in the area where the chain is meshed with the sprocket, the proximity switch must be arranged in the area where the chain is not meshed with the sprocket.
In the latter case, the proximity switch must be placed in the space between the two sprockets inside the chain, making it difficult to secure a space for arranging the proximity switch.

SUMMARY OF THE INVENTION The present invention has been devised by paying attention to such problems, and it is an object of the present invention to provide a rotational speed measuring device suitable for securing the reading accuracy of the proximity switches and securing the arrangement space for the proximity switches.

A rotational speed measuring device of the present invention is a rotational speed measuring device for measuring the rotational speed of any rotating element of a power transmission mechanism comprising a pair of sprockets and a chain wound around the pair of sprockets. a protrusion formed on one end side of a pin that interconnects plates in the chain so as to protrude from the outer surface of the plate; and a proximity sensor for detecting proximity of the protrusion , and a plurality of Some of the pins are provided with the protrusion on the one end side, and the remaining pins of the plurality of pins are not provided with the protrusion on the one end side.
Another rotational speed measuring device of the present invention is a rotational speed measuring device for measuring the rotational speed of any rotating element of a power transmission mechanism comprising a pair of sprockets and a chain wound around the pair of sprockets. a protrusion formed so as to protrude from the outer surface of the plate on one end side of a pin that interconnects plates in the chain; and a proximity sensor that detects proximity of the protrusion, The detection part of the proximity sensor is characterized in that it is oriented toward the rotation track from the outside or the inside of the rotation track of the chain.

Preferably, the protrusion is formed by one end of the pin .
It is preferable that a rotation direction pattern is formed by a combination of the pin provided with the protrusion on the one end side and the pin without the protrusion on the one end side.
All of the plurality of pins have the same length and the same shape, some of the pins are arranged so that the projecting portion comes to the one end side, and the remaining pins are opposite to the one end side. It is preferable that the projection be arranged so as to come to the end side .
It is preferable to further include a timer for measuring time associated with the detection by the proximity sensor, and a calculation unit for calculating the rotation speed from detection information by the proximity sensor and time information by the timer.

According to the rotational speed measuring device of the present invention, it becomes easy to ensure the reading accuracy of the proximity switch, and it becomes easy to ensure the arrangement space of the proximity switch.

It is a figure which shows the chain and proximity sensor of the rotational speed measuring apparatus concerning 1st Embodiment, (a) is a principal part perspective view, (b) is a principal part side view. 1 is a configuration diagram of a hybrid vehicle drive device equipped with a rotation speed measuring device according to a first embodiment; FIG. 1 is a perspective view of a transmission provided in a driving device equipped with a rotational speed measuring device according to the first embodiment; FIG. It is a figure which shows the chain and proximity sensor of the rotational speed measuring apparatus concerning 1st Embodiment, seeing from the outer peripheral side of a chain. FIG. 4 is a side view of a chain for explaining locations of proximity sensors of the rotation speed measuring device according to the first embodiment; It is a side view of the chain explaining the modification of the arrangement|positioning location of the proximity sensor of the rotation speed measuring apparatus concerning 1st Embodiment. It is a principal part perspective view which shows the chain of the rotation speed measuring apparatus concerning 2nd Embodiment.

Embodiments of the present invention will be described below with reference to the drawings. It should be noted that the embodiments shown below are merely examples, and there is no intention to exclude various modifications and application of techniques that are not explicitly described in the following embodiments. Each configuration of the following embodiments can be modified in various ways without departing from the gist thereof, and can be selected or combined as necessary.

[First embodiment]
〔Device configuration〕
As shown in FIGS. 2 and 3, the rotational speed measuring device according to this embodiment is installed in a driving device 1 mounted on a vehicle. Further, the vehicle according to the present embodiment includes a drive device 1, an internal combustion engine (engine) 2, a transmission 4 having a belt-type continuously variable transmission (hereinafter referred to as CVT) 3, and a drive assist electric motor (motor generator). , hereinafter simply referred to as a motor) 5.

The transmission 4 includes a torque converter 40 with a direct coupling clutch, a forward/reverse switching mechanism 42 formed of planetary gears, and a CVT 3. It has a belt 33 that is wrapped around. A torque converter 40 with a direct coupling clutch is connected to the engine 2 and a turbine shaft 40A is connected to a forward/reverse switching mechanism 42 . The forward/reverse switching mechanism 42 is connected to the input shaft (rotating shaft) 3A (that is, the input pulley 31) of the CVT 3. , and is drivingly connected to drive wheels (not shown) of the vehicle via a differential mechanism 7 . In FIG. 3, the axes of the input shaft 3A and the output shaft 3B of the CVT 3 are indicated by S1 and S2, and the axis of the axle shaft 7A connected to the differential mechanism 7 is indicated by S3.

Motor 5 is connected to input shaft 3A of CVT 3 via power transmission mechanism 10 .
The power transmission mechanism 10 includes a pair of sprockets 11 and 12 and a chain 13 wound around the sprockets 11 and 12. The sprocket 11 is fixed to the rotating shaft 51 of the motor 5, and the sprocket 12 is It is fixed to the input shaft 3A of the CVT3. In FIG. 3, the axis of the rotary shaft 51 of the motor 5 is denoted by S4.

The power transmission mechanism 10 includes a wall portion 14 formed integrally with one end side wall portion 4a of the TM case (transmission case) 4C and one end side wall portion 20a of the casing 20 of the motor 5, and is attached to the wall portion 14 in a liquid-tight manner. It is installed in the accommodation space 16 between the cover 15 and the cover 15 . Here, the sprocket 12 on the output side has a larger diameter than the sprocket 11 on the input side, and the power transmission mechanism 10 also functions as a reduction mechanism that reduces the rotational speed of the motor 5 .

As shown in FIGS. 1, 4, and 5, the chain 13 of this embodiment has a plurality of link plates (hereinafter simply referred to as plates) 131 that are bendable by a plurality of connecting pins (hereinafter simply referred to as pins) 133. It is a silent chain that is connected. The chain 13 has a plurality of link plate rows (hereinafter simply referred to as plate rows) 131L each formed by endlessly lining up a plurality of plates 131 in the direction of rotation of the chain 13 and extending in the width direction of the chain 13 (thickness direction of the plates 131). Adjacent plate rows 131</b>L are arranged side by side and arranged to be shifted in the direction of rotation of the chain 13 by half the length of the plates 131 (half pitch).

Two pin holes 132 are formed in each plate 131 while being shifted in the rotational direction, and the plate rows 131L arranged in the width direction are connected to each other by pins 133 inserted through the pin holes. The plates 131 arranged in the rotational direction are endlessly connected to each other via the plate rows 131L adjacent in the direction.
Guide plates 134 are provided on both sides of the chain 13 in the width direction to sandwich the sprockets 11 and 12 from the plate thickness direction of the plate 131 to prevent the chain 13 from coming off the sprockets 11 and 12 .

Further, as shown in FIG. 5, the wall portion 14 has an oil supply port 80 for introducing lubricating oil into the housing space 16 and supplying it to the sprockets 11, 12 and the chain 13, and supplying the lubricating oil in the housing space 16. An oil drain hole 82 is provided to allow the oil to flow out to the inside of the TM case 4C. The lubricating oil also has a function of cooling the sprockets 11 and 12 and the chain 13, and a sufficient amount of lubricating oil is supplied into the housing space 16 to ensure these functions. For this reason, a lubricating oil reservoir 17 in which lubricating oil normally stays is formed in the lower part (region A1 shown in FIG. 5) of the housing space 16 .

Rotation speed measuring device 100 measures the rotation speed of rotation shaft 51 of motor 5 and input shaft 3A of CVT 3 . The rotating shaft 51 of the motor 5 and the input shaft 3A of the CVT 3 rotate at a constant rotational speed ratio corresponding to the gear ratio of the sprockets 11 and 12. It corresponds to the rotation speed and the rotation speed of the chain 13 . The rotation speed measuring device 100 measures the rotation speed by focusing on the chain 13 .

Rotational speed measuring device 100 includes a proximity sensor 101 that converts information on the existence of a detection target into an electrical signal; A timer 103 for measuring time and a calculation unit 104 for calculating a rotational speed from information detected by the proximity sensor 101 and time information by the timer 103 are provided. ing.

Since the pins 133 of the chain 13 are intermittently provided at regular intervals, when the movement of the pins 133 is monitored from fixed points around the chain 13, the pins 133 pass one after another as the chain 13 rotates. By capturing the passage of this pin 133 by the proximity sensor 101, the output (for example, output voltage) of the proximity sensor 101 changes. The passing speed of the pin 133, that is, the rotational speed of the chain 13 can be calculated from the relationship between the output change and time.

As for the unevenness due to the pin 133, the portion where the end of the pin 133 (protruding portion 135 described later) that protrudes from the outer surface of the guide plate 134 exists is a convex portion, and the portion where the end of the pin 133 (protruding portion 135) does not exist. is formed as a concave portion. The proximity sensor 101 outputs a pulse signal corresponding to this unevenness.

As shown by the solid line in FIG. The side surface is regarded as a convex portion and reacted, and since there is nothing between the adjacent pins 133, it is regarded as a concave portion and reacted.

4, when the detection portion 101A is directed from the side of the chain 13 to the area through which the pin 133 passes, the detection portion 101A of the proximity sensor 101 uses the head of the pin 133 as a convex portion. It catches and reacts, and catches and reacts to the outer surface of the guide plate 134 between adjacent pins 133 as recesses. That is, the concave-convex body 102 is formed by the outer surface of the guide plate 134 and the end of the pin 133 (protruding portion 135).

Each end of the pin 133 normally protrudes from the outer surface of the guide plate 134, but in this embodiment, a protruding portion protruding from the outer surface of the guide plate 134 is provided at one end of the pin 133. 135 is formed so that the end portion (side portion or head portion) of the pin 133 can be more clearly perceived as a convex portion. Note that the one end side of the pin 133 indicates one side in the width direction of the chain 13 . Further, in the present embodiment, the protruding portion 135 is formed by arranging the end portion (one end portion) of the pin 133 on the one end side so as to protrude further from the outer surface of the guide plate 134 .

In this embodiment, as shown in FIGS. 1 and 4, the proximity sensor 101 is arranged outside the rotational orbit of the chain 13, and the detection portion 101A is positioned in the passage area of the pin 133 along the rotational orbit of the chain 13. is oriented to With this configuration, the output of the proximity sensor 101 can be clearly changed by capturing the sides of the pins 133 as protrusions and capturing the portions where nothing exists between the pins 133 as recesses by the detection unit 101A.

By the way, the portion of the chain 13 that meshes with the sprockets 11 and 12 rotates along the outer circumference (tooth portion) of the sprockets 11 and 12, but the portion between the sprockets 11 and 12 that does not mesh with the sprockets 11 and 12 rotates along the sprockets 11 and 12. Shaking due to vibration occurs and fluctuates inward and outward with respect to the rotation orbit. Due to this shaking, the pin 133 may move out of the detection range of the proximity sensor 101 and the pin 133 may not be detected.

In addition, since the chain 13 stretches, the interval between the output pulses of the proximity sensor 101 changes depending on the presence or absence of this stretch, and there is a possibility that the rotation speed cannot be measured correctly.
Furthermore, lubricating oil remains in the housing space 16 that houses the chain 13 and the sprockets 11 and 12. If the lubricating oil contains foreign matter (contamination) such as iron powder, the proximity sensor 101 may cause an erroneous detection.

Therefore, as shown in FIG. 5, the proximity sensor 101 is located in areas A2 and A3, which are meshing areas where the chain 13 meshes with the sprockets 11 and 12 and which are less susceptible to the lubricating oil remaining in the housing space 16. to place The meshing area of the chain 13 mentioned above is the area in which the sprockets 11 and 12 are completely meshed, and the vicinity of this area where the chain 13 is completely meshed. It shall include an area that does not affect or an area that can tolerate the influence.

The area A2 where the chain 13 meshes with the sprocket 11 is less susceptible to the lubricating oil remaining in the housing space 16, so the entire area A2 is suitable for disposing the proximity sensor 101.
On the other hand, in the region where the chain 13 meshes with the sprocket 12, there is a lubricating oil reservoir 17, which is a vertically upper region of the sprocket 12 vertically above the lubricating oil reservoir 17 and is lubricated by the rotation of the chain 13 and the sprockets 11 and 12. A region A4 where the oil is swirled up is affected by the lubricating oil remaining in the housing space 16 . Therefore, in the area where the chain 13 meshes with the sprocket 12, the area A3 excluding the lubricating oil reservoir 17 and the area A4 is a suitable area for arranging the proximity sensor 101. FIG.

The lubricating oil stays under the sprocket 12 on the input pulley 31 side. false positives may occur. If the area A4 is removed to avoid this, the area A3 suitable for disposing the proximity sensor 101 is limited only near the upper portion of the sprocket 12 on the sprocket 12 side.

Further, depending on the configuration around the motor 5 and the type of the proximity sensor 101, the proximity sensor 101 may be affected by the magnetic field generated by the motor 5 and may not operate normally.
When the proximity sensor 101 is arranged in consideration of this point, it is preferable to arrange the proximity sensor 101 outside the area A5 affected by the magnetic field generated by the motor 5, as shown in FIG. In this case, since the area A2 is included in the area A5 affected by the magnetic field, it is optimal to place the proximity sensor 101 in the area A3.

[Action and effect]
Since the rotation speed measuring device 100 according to the present embodiment is configured as described above, the rotation speed of each part of the power transmission mechanism 10 can be accurately measured using the pin 133 of the chain 13 .

In particular, one end of the pin 133 is formed with a protruding portion 135 protruding from the outer surface of the guide plate 134 so that the proximity sensor 101 can detect the protruding portion 135 as a protruding portion and between the protruding portions 135 . Since the rotation of the chain 13 is measured by capturing the space of the chain 13 as a recess, the output of the proximity sensor 101 clearly changes, and the chain 13 and the accompanying sprocket 11 (that is, the motor 5) and sprocket 12 (that is, the input The rotational speed of each rotating element associated with the drive train 10, such as the pulley 31), can be measured.

In addition, in the present embodiment, the proximity sensor 101 is arranged outside the rotation orbit of the chain 13, and the detection part 101A is directed to the passage area of the pin 133. Since the portions where nothing exists between them are treated as recesses, the output of the proximity sensor 101 can be clearly changed from this point as well, and the rotation speed can be measured with high accuracy.
In addition, by using the uneven body 102 of the chain 13 as a detection target, the proximity switch 101 can be arranged outside the rotation track and the proximity switch 101 can be arranged more freely.

Further, as shown in FIG. 5, proximity sensors are located in areas A2 and A3, which are meshing areas where the chain 13 meshes with the sprockets 11 and 12 and are areas that are less susceptible to the lubricating oil remaining in the housing space 16. Since 101 is arranged, the rotation speed can be measured with high accuracy.

In other words, at a portion where the chain 13 is not meshed with the sprockets 11 and 12, vibration due to string vibration occurs or the chain 13 stretches, so there is a possibility that the pin 133 cannot be detected properly. However, since the proximity sensor 101 is arranged outside such an area, the rotational speed can be measured with high accuracy.

Lubricating oil remains in the accommodation space 16 that accommodates the chain 13 and the sprockets 11 and 12, and if the lubricating oil contains contaminants such as iron powder, the proximity sensor 101 will be erroneously detected. Although there is a possibility that detection may occur, since the proximity sensor 101 is arranged outside such an area, the rotation speed can be measured with high accuracy.

Furthermore, as shown in FIG. 6, if the proximity sensor 101 is arranged in the area A3 in consideration of the influence of the magnetic field generated by the motor 2, the proximity sensor 101 will not be affected by the magnetic field generated by the motor 2. Since it operates properly, it is possible to measure the rotation speed with high accuracy.

[Second embodiment]
〔Device configuration〕
As shown in FIG. 7A, the rotation speed measuring device 100A according to the present embodiment differs from the first embodiment in the configuration of one end of the pin 133, which is the detection target of the detection unit 101A of the proximity sensor 101. , is configured in the same manner as the first embodiment except for this point. In FIG. 7(a), the same reference numerals as those in FIG. 1 denote the same items, and the description thereof is omitted.
In the first embodiment, the protruding portion 135 is formed on one end side of all the pins 133, but in the present embodiment, as shown in FIG. 133 has a protrusion 135 on one end thereof and the remaining pins do not have a protrusion 135 on one end thereof.

A combination of the pin 133 having the projection 135 on one end side and the pin 133 not having the projection 135 on the one end side forms a pattern in the rotational direction.
That is, the proximity sensor 101 responds to the pin 133 with the projecting portion 135 and outputs an ON signal pulse, and the proximity sensor 101 does not respond to the pin 133 without the projecting portion 135. , do not output ON signal pulses. Therefore, the proximity sensor 101 outputs a signal pattern as shown in FIG. 7(b). As shown in FIG. 7(b), since the signal pattern has directionality, the direction of rotation can be determined by distinguishing between the forward rotation pattern and the reverse rotation pattern.

In addition, in this embodiment, the pins 133 themselves are the same (same length and same shape) having a protrusion 135 at one end. A pin 133 having no protrusion 135 is provided on one end side. Therefore, it is sufficient to prepare a single type of pin 133, and it is not necessary to prepare a plurality of types.

[Action and effect]
Since the rotation speed measuring device 100 according to the present embodiment is configured as described above, it is possible to obtain the same actions and effects as those of the first embodiment, and in addition, it is possible to detect the direction of rotation as well. is obtained.
In addition, by using the same pin 133 and reversing the mounting direction, a rotational direction pattern is formed and the rotational direction is detected, so an increase in component cost can be suppressed.

[others]
Although the embodiments have been described above, the present invention can be implemented by appropriately modifying the above embodiments without departing from the scope of the invention.
For example, in the above embodiment, a silent chain is used as an example of a chain, but an appropriate type of chain such as a general roller chain can be applied.

Further, in each of the above-described embodiments, the projecting portion 135 is formed by arranging one end of the pin 133 so as to protrude from the outer surface of the guide plate 134, but the pin 133 is particularly attached to the guide plate. Even if the pin 133 is not arranged to overhang the outer surface of the guide plate 134 to a greater extent (i.e., with the normal axial placement of the pin 133), the pin 133 may be positioned so that both ends of the pin 133 extend beyond the outer surface of the guide plate 134 to some extent. can be used as the projecting portion 135 as it is.
Of course, a projection projecting in the axial direction may be formed on one end of the pin 133 and this projection may be used as the projecting portion 135 .

Furthermore, in the above embodiment, the power transmission mechanism 10 comprising a chain and sprockets is applied to the transmission 4, but the power transmission mechanism 10 can be applied not only to the transmission 4, but also to various other devices. can be applied to measure the rotation of

1 drive device 2 internal combustion engine (engine)
3 Belt type continuously variable transmission (CVT)
3A Input shaft of CVT3 4 Transmission 4C TM case (transmission case)
4a One end side wall portion of TM case 4C 5 Drive assist electric motor (motor)
6 Final Reduction Mechanism 7 Differential Mechanism 10 Power Transmission Mechanism 11, 12 Sprocket 13 Chain 14 Wall 15 Cover 16 Housing Space 17 Lubricating Oil Pool 20 Casing of Motor 2 20a Side Wall at One End of Casing 20 31 Input Pulley 32 Output Pulley 33 Belt 40 torque converter with direct coupling clutch 42 forward/reverse switching mechanism 80 oil supply port 82 oil drain hole 100 rotational speed measuring device 101 proximity sensor 101A detection unit of proximity sensor 101 102 uneven body (unevenness)
103 timer 104 arithmetic unit 131 link plate (plate)
132 pin hole 133 connecting pin (pin)
134 guide plate 135 protrusion A2, A3 arrangement area of proximity sensor 101

Claims (6)

A rotation speed measuring device for measuring the rotation speed of any rotating element of a power transmission mechanism comprising a pair of sprockets and a chain wound around the pair of sprockets,
a protrusion formed on one end of a pin that connects plates in the chain so as to protrude from the outer surface of the plate;
A proximity sensor that detects the proximity of the protrusion ,
Some of the plurality of pins have the protrusion on the one end side, and the remaining pins of the plurality of pins do not have the protrusion on the one end side.
A rotational speed measuring device characterized by: A rotation speed measuring device for measuring the rotation speed of any rotating element of a power transmission mechanism comprising a pair of sprockets and a chain wound around the pair of sprockets,
a protrusion formed on one end of a pin that connects plates in the chain so as to protrude from the outer surface of the plate;
A proximity sensor that detects the proximity of the protrusion,
The detection part of the proximity sensor is oriented toward the rotation track from the outside or the inside of the rotation track of the chain.
A rotational speed measuring device characterized by: 3. The rotating speed measuring device according to claim 1 , wherein the protrusion is formed by one end of the pin. 3. The rotational speed measurement according to claim 1, wherein a combination of the pin having the protrusion on the one end side and the pin not having the protrusion on the one end side forms a rotation direction pattern. Device. All of the plurality of pins have the same length and the same shape, some of the pins are arranged so that the projecting portion comes to the one end side, and the remaining pins are opposite to the one end side. 2. The rotating speed measuring device according to claim 1 , wherein said projection is arranged on the end side. a timer that measures the time associated with detection by the proximity sensor;
The rotation speed measuring device according to any one of claims 1 to 5 , further comprising a calculation unit for calculating the rotation speed from detection information from the proximity sensor and time information from the timer. .

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