JPH0587963B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

TECHNICAL FIELD The present invention relates to an electromagnet that can increase or decrease attraction force with less electric power by combining with a permanent magnet.

[Conventional technology]

In the past, there were electromagnets that were configured in combination with magnets. This was configured to weakly control the magnetic force by exciting an electromagnet in a direction that canceled out the magnetic field of the magnet. In addition, the means for switching mechanisms such as the threads of conventional knitting machines is composed of magnets, and when the direction of movement of the carriage is reversed, the attraction between the sliding bar and the magnet causes the magnet to A force is generated that tries to hold back. By this force, the mechanism is configured to switch from the forward route state to the return route state to prepare for the return route formation.

[Problem to be solved by the invention]

However, with conventional electromagnets combined with the magnets described above, in order to keep the magnetic force weak, it is necessary to continuously supply current to the electromagnet to excite it, which poses a problem in that it consumes a large amount of energy. In the knitting machine switching means using magnets as described above, even when the carriage is running on the sliding bar while knitting after reversing, there is a strong attraction force between the magnet and the sliding bar. This not only puts a load on the carriage and requires wasted driving energy, but also causes the carriage to travel while being strongly pressed against the sliding bar due to the above-mentioned attractive force, which causes the problem that the sliding parts are likely to wear out. Occur. In order to solve this problem, it is possible to use electromagnets instead of the magnets mentioned above, but with conventional electromagnets, it is necessary to make them large in order to obtain sufficient adsorption force, so it is difficult to use when space is limited. It was inappropriate to attach it to a carriage. Even if the magnet is attached, a large amount of power must be continuously supplied during the excitation time, resulting in a problem of increased heat generation. In particular, the smaller the electromagnet, the worse the heat dissipation effect, so it has been inappropriate to use an ordinary electromagnet as a means for switching the carriage. Therefore, the present invention was made with the aim of solving these various problems and realizing an electromagnet that can obtain the necessary magnetic force only when necessary.

[Means to solve the problem]

In the electromagnet according to the present invention, the semi-hard magnetic member provided with the excitation coil, the magnet, and the attracted magnetic body constitute a first magnetic circuit, and the magnet and the soft magnetic member constitute the first magnetic circuit. By configuring a second magnetic circuit different from the magnetic circuit and providing an excitation coil drive means for exciting the excitation coil for a short time in the same direction or in the opposite direction to the direction of the magnetic field by the magnet, the first A measure was taken to control the attraction force of the magnetic body to be attracted in the magnetic circuit by switching between strong and weak states. In the knitting machine according to the present invention, when the direction of movement of the carriage traveling along the sliding bar made of magnetic material is reversed at both ends of the knitting width,
In a knitting machine equipped with a switching means for switching knitting mechanisms such as stitches and cams, a first magnetic circuit includes a semi-hard magnetic member having an excitation coil, a magnet, and the sliding bar; An electromagnet having a second magnetic circuit different from the first magnetic circuit composed of a magnet and a soft magnetic material member is disposed on the carriage at a position facing the sliding bar, and the knitting width is means for outputting a carriage reversal start signal at a reversal position at an end of the cartridge; and means for outputting a carriage reversal completion signal at a position slightly inside the reversal position or at a timing slightly delayed from the carriage reversal start signal. , an excitation coil that excites the excitation coil for a short time in the same direction as the magnetic field of the magnet by the carriage reversal start signal, and excite the excitation coil for a short time in the opposite direction to the magnetic field of the magnet by the carriage reversal completion signal. driving means, and when reversing the running direction of the carriage at both ends of the knitting width, the magnetic flux density of the first magnetic circuit of the electromagnet is increased only between a carriage reversal start signal and a carriage reversal completion signal. Accordingly, the switching means is activated by increasing the attraction force between the electromagnet and the sliding bar.

[Effect]

The action of the electromagnet according to the present invention is shown in Figures 1 and 2.
This will be explained with reference to FIG. In the electromagnet of the present invention, exciting coils 5, 6
The semi-hard magnetic bodies 2, 3 and the magnet 1 constitute a first magnetic circuit A to attract the magnetic body 4 to be attracted, and a second magnetic circuit A is configured to attract the magnetic body 4 to be attracted.
A magnetic circuit B was formed by the magnet 1 and the soft magnetic member 7. That is, in the magnet 1, a first magnetic circuit A formed by the semi-hard magnetic members 2 and 3 and a second magnetic circuit B formed by the magnet 1 and the soft magnetic member 7 are arranged in parallel. is formed. In the electromagnet 1, the excitation coils 5, 6
When the magnet 1 is not energized, the magnetic lines of force of the magnet 1 mainly pass through the second magnetic circuit B of the soft magnetic member 7, which has a higher magnetic permeability, and pass through the first magnetic circuit B, which has a lower magnetic permeability.
Only a small amount of leakage magnetic flux passes through the magnetic circuit A, and the force (F1) for attracting the attracted magnetic body 4 is weak.
The semi-hard magnetic bodies 2 and 3 are not saturated with this leakage magnetic flux. However, when the excitation coil 5 is energized and excited in the same direction X as the magnetic field Z generated by the magnet 1, the magnetic field Hs
When given, the semi-hard magnetic members 2 and 3 constituting the first magnetic circuit A obtain saturation magnetization Ms, have high magnetic permeability, and increase magnetic flux density, so that they strongly attract the magnetic material 4 to be attracted. become. At this time, even if the current to the excitation coil 5 is cut off, residual magnetization Mr remains in the semi-hard magnetic members 2 and 3 due to their residual magnetization characteristics, and the magnetic flux density of the first magnetic circuit A is high. This maintains a strong adsorption force (F2). Here, the excitation coil 6 is energized to be excited in the direction Y opposite to the direction Z of the magnetic lines of force by the magnet 1, and the semi-hard magnetic members 2 and 3 constituting the first magnetic circuit A are
When we apply a reverse magnetic field greater than its coercive field (-Hc),
The residual magnetization of the semi-hard magnetic members 2 and 3 becomes zero or less, and this state is maintained even when the electricity is turned off. Therefore, the second magnetic circuit B has a higher magnetic permeability and a higher magnetic flux density, and the magnetic flux density of the first magnetic circuit A becomes lower, and the force (F1 ) becomes weaker. That is, the semi-hard magnetic material member in the present invention is a magnetic material that can obtain residual magnetization. In this way, just by energizing the magnet in the opposite direction only at the moment when the magnetic force is switched between strong and weak,
Even when the current is turned off, the magnetic force can be maintained in either a strong or weak state. According to the knitting machine according to the present invention, the means for switching mechanisms such as the dowel and cam according to the direction of carriage movement is constituted by the electromagnet having the above structure. When the excitation coil is energized to excite it in the same direction as the magnetic flux generated by the built-in magnet, the high magnetic flux density of the first magnetic circuit A' is maintained even if the current supply is stopped. Therefore, the sliding bar as the magnetic body to be attracted is strongly attracted, and a resistance force in a direction opposite to the direction in which the carriage moves acts on the switching means, thereby switching the mechanism. When the switching of the mechanism such as the cam is completed, when the excitation coil of this electromagnet is energized in the opposite direction, the magnetic flux density of the first magnetic circuit A' decreases, and the current Even if the supply is stopped, the magnetic flux density of the first magnetic circuit A' remains low. Therefore, the attraction force to the sliding bar as the magnetic body to be attracted becomes weaker, so the resistance force that tries to prevent the carriage from moving is weakened, and the carriage runs smoothly.

【Example】

Embodiments of the electromagnet according to the present invention will be explained in detail below based on the drawings. FIG. 1 is a side sectional view of an embodiment of the electromagnet of the present invention, and FIG. 2 is a timing chart for switching the strength of the electromagnet. In the drawing, 1 is a magnet in which a hard magnetic material is magnetized to form an S pole 1A and an N pole 1B, and 2 is a magnet whose end 2A is the N pole of the magnet 1.
A semi-hard magnetic member 3 is joined to the pole 1B, 3 is a semi-hard magnetic member whose end 3A is joined to the S pole 1A of the magnet 1, 4 is a magnetic member to be attracted, and 5 and 6 are the half-hard magnetic members, respectively. This is an excitation coil wound around hard magnetic members 2 and 3. 8 and 9 are the excitation coils 5 and 6
It is a switch that connects the DC power supply 10 to the DC power supply 10 for a short time
When the switch 8 is turned on, a downward magnetic field X is generated in the excitation coil 5, and when the switch 9 is turned on, a downward magnetic field Y is generated in the excitation coil 6. Reference numeral 7 denotes a soft magnetic member whose both ends are joined to the ends 2A, 3A of the semi-hard magnetic members 2, 3. In this case, the magnet 1 is 3.5Ω×11.9Ω
A combination of two ×7Ω magnets is used, the semi-hard magnetic members 2 and 3 are made of carbon steel (S45C) with a thickness of 4Ω, and the excitation coils 5 and 6 have a diameter of
A coil having a resistance of 0.18Ω, 550 turns, a length of 11Ω, and a resistance value of 15Ω was used, and the soft magnetic member 7 was made of electromagnetic soft iron (SUYP) with a thickness of 3Ω. The magnet 1, the semi-hard magnetic member 2, the attracted magnetic body 4, and the semi-hard magnetic member 3 constitute a first magnetic circuit A, and the magnet 1, the end portion 2A of the semi-hard magnetic member 2, the soft The magnetic member 7 and the end portion 3A of the semi-hard magnetic member 3 constitute a second magnetic circuit B. In the electromagnet 11 having the above configuration, in the initial state, the magnetic flux generated by the magnet 1 mainly flows toward the second magnetic circuit B made of a softer magnetic material, and forms the first magnetic circuit A. The magnetic flux density of the semi-hard magnetic members 2 and 3 is low because it is only the leakage magnetic flux from the magnet 1. Therefore, the magnetic body 4 to be attracted
The adsorption power is weak (F1). Therefore, when the switch 8 is turned on, the downward magnetic field X is generated in the excitation coil 5, and a strong clockwise magnetic field is generated in the first magnetic circuit A. Therefore, the magnetic body 4 to be attracted is attracted with a strong force. Next, when the switch 8 is turned off, the excitation current in the excitation coil 5 disappears, but residual magnetization remains in the semi-hard magnetic members 2 and 3 due to their hysteresis characteristics. A strong clockwise magnetic flux continues to exist. Therefore, the attracted magnetic body 4 continues to be attracted with a strong force (F2). That is, in this state, the strong attraction force (F2) continues even though no power is supplied to the excitation coils 5 and 6.
At this time, the measured sliding force was 1.0 kgf. Note that this sliding force is the force required to cause the electromagnet to slide between the attracted member and the electromagnet. Next, when the switch 9 is turned on, the downward magnetic field Y is generated in the excitation coil 6, and the first
A strong magnetic field exceeding the coercive field of the semi-hard magnetic material in the counterclockwise direction is generated in the magnetic circuit A, and this magnetic field causes the residual magnetization of the semi-hard magnetic material members 2 and 3 to be below zero, and the first In the magnetic circuit A, there is only a slight leakage magnetic flux due to the magnet 1, and the magnetic body 4 to be attracted
The adsorption force becomes weaker (F1). Next, when the switch 9 is turned off, the excitation coil 6 is not excited, and high residual magnetization cannot be given to the semi-hard magnetic members 2 and 3 of the first magnetic circuit A only by the leakage magnetic flux from the magnet. First, a state is maintained in which only a small amount of leakage magnetic flux exists in the first magnetic circuit A. Therefore, the force that attracts the magnetic body 4 to be attracted remains weak (F1).
The actual measured sliding force at this time was 0.3 kgf. Therefore, by switching the attraction force of the electromagnet to be strong or weak,
We were able to obtain a change in sliding force of 0.7Kgf. It is sufficient that the excitation coils 5 and 6 are energized for several milliseconds. Note that the material composition of this electromagnet 11 is not limited to that shown in FIG. For example, if only one magnet of 3.5Ω x 11.9Ω x 7Ω is used as the magnet 1, the sliding force will be 0Kgf and 0.4Kgf.
Kgf, and if carbon steel (S45C) is used as the soft magnetic member 7, the sliding force can be switched between 0.4 Kgf and 1.1 Kgf,
If carbon steel (S45C) is used as the soft magnetic member 7 and electromagnetic soft iron (SUYP) is used as the semi-hard magnetic members 2 and 3, the sliding force will be 0.45Kgf and 0.7Kg.
I was able to switch to f. Therefore, when electromagnetic soft iron (SUYP) was used for both the soft magnetic member 7 and the semi-hard magnetic members 2 and 3, the sliding force hardly changed. In order to obtain a change in sliding force of 0.5 Kgf or more in this manner, it is inconvenient to use electromagnetic soft iron as the semi-hard magnetic members 2 and 3, and it can be said that hard carbon steel of approximately S45C or higher is appropriate. Note that instead of two excitation coils with different winding directions, the polarity of the current supplied to one excitation coil may be changed, and the winding method is not limited to the above embodiment. Of course, it is also possible to use a bi-airer or a uniform airer, for example. Next, embodiments of the knitting machine according to the present invention will be explained in detail based on the drawings. Fig. 3 is a plan view structural diagram with a part of the carriage of the knitting machine according to the present invention cut away, Fig. 4 is a partially enlarged sectional view of the magnetic attraction member of the carriage, and Fig. 5 is a control of the knitting machine. FIG. 6 is a block diagram of the circuit and a timing chart for switching the suction force of the knitting machine. In FIGS. 3 to 6, a raised ridge 24 is fixed to the main plate 23 of the carriage 21, and raised ridges 22a and 22b are supported so as to be movable up and down.
are provided facing the cam surfaces 24a, 24b. The springs 31 are the springs 22a and 22b.
a and 31b so as to move diagonally downward along the groove. Guide plates 13a, 13
The rollers 12a and 12b provided on the top surface of b are
It is in contact with a cam plate 25 that is supported by guide members 26a and 26b of the base plate 23 so as to be able to slide in parallel to the direction of movement of the carriage 21. The cam plate 25 has a concave portion 32 formed in the center thereof,
The rollers 12a, 12b are received near the inclined surfaces 32a, 32b of the concave portion 32. Further, step portions 27a and 27b are formed near both ends of the cam plate 25, and when the cam plate 25 moves from side to side, the step portions 27a and 27b
7a, 27b abut against guide members 26a, 26b, and prevent further movement of cam plate 25. A magnetic attraction member 28 is provided on the cam plate 25, felt is fitted and fixed in the recesses provided at both ends of the magnetic attraction member 28, and an electromagnet 41 capable of switching the attraction force between strong and weak states is provided in the middle part. As shown in FIG. 4, this magnetic attraction member 28 includes a magnet 42, a soft magnetic member 43, semi-hard magnetic members 44a and 44b, and excitation coils 45a and 4.
The electromagnet 41 includes an electromagnet 5b. The magnet 42, the semi-hard magnetic member 44a, the sliding bar 29, and the semi-hard magnetic member 44b constitute a first magnetic circuit A', and the magnet 42 and the soft magnetic member 43 constitute a first magnetic circuit A'. This constitutes the second magnetic circuit B'. When the attraction force of this electromagnet 41 is increased,
This magnetic attraction member 28 strongly attracts the sliding bar 29 extending in the moving direction of the carriage 21, and is configured so that when the attraction force of the electromagnet 41 is weakened, the attraction force becomes weaker. The control unit 51 constantly obtains the pulse signal γ indicating the position of the carriage 21 from the encoder 56 that scans a pattern such as a magnetic or optical stripe provided along the sliding bar 29. When the carriage 21 reaches the end of the knitting width after knitting one course, the processing circuit 55
, the count value of the pulse signal γ, the knitting width left end setting device 53 and the knitting width right end setting device 54
The carriage reversal start signal α is output when the values set in and are matched, and the carriage reversal is completed after a predetermined period of time (or after counting a predetermined number of pulse signals γ) of this carriage reversal start signal α. Outputs signal β. In response to the input of this carriage reversal start signal α, the electromagnet drive circuit 52 supplies an excitation current that generates a magnetic field in the same direction as the magnetic field of the magnet 42 to the excitation coil 45a of the electromagnet 41 for a short period of about several milliseconds. do. Then, the magnetic flux density of the first magnetic circuit A' increases, and the sliding bar 29 is strongly attracted. Note that when the carriage reversal start signal α is input to the carriage drive device 57, the traveling direction of the carriage 21 is reversed. Then, upon receiving the carriage reversal completion signal β, the electromagnet drive circuit 52 causes the electromagnet 41 to
An excitation current that generates a magnetic field in the opposite direction to the magnetic field of the magnet 41a is supplied to the excitation coil 45b for a short period of about several milliseconds. Then, the semi-hard magnetic member 44a of the electromagnet 41,
The residual magnetization of 44b disappears, and the second magnetic circuit
Although the magnetic flux density of B' becomes high, the magnetic flux density of the first magnetic circuit A' becomes low, and the force that attracts the sliding bar 29 becomes weak. In the knitting machine having the above configuration, the carriage 21 is now in a state in which the concave portion 32 of the cam plate 25 is positioned on the rear side in the direction of carriage movement and the stepped portion 27b is in contact with the guide member 26b, as shown in FIG. Suppose that the robot is moving while organizing in the direction of the arrow. At this time, the roller 12a of the leading arm 22a is moving up the inclined surface 32a of the cam plate 25 against the elastic force of the spring 31a, so the arm 22a is in the raised position. On the other hand, the roller 12b on the trailing side ridge 22b moves down the inclined surface 32b of the cam plate 25 to be located in the concave portion 32 due to the elastic force of the spring 31b, so that the ridge 22b is at a predetermined lowered position. be. Next, when the carriage 21 completes knitting of a predetermined width and reverses, the control section 51 outputs a carriage reversal start signal α. Electromagnet drive circuit 52
The attraction force of the electromagnet 41 is strengthened by this carriage reversal start signal α, and the magnetic attraction member 28 is strongly attracted to the sliding bar 29. If the carriage 21 continues to reverse and starts moving to the left, the magnetic adsorption member 2
8 is attached to the sliding bar 29, so the cam plate 25
cannot start moving to the left and tries to remain stationary and slides to the right relative to the base plate 23 of the carriage 21. At this time, the roller 12a on the side of the thread 22a moves down the inclined surface 32a of the cam plate 25 due to the elastic force of the spring 31a, and
The roller 12b on the side of the dowel 22b moves up the inclined surface 32b of the cam plate 25 against the elastic force of the spring 31b. Then, as the stepped portion 27a of the cam plate 25 comes into contact with the guide member 26a, the cam plate 25 is no longer able to remain stationary, and starts moving to the left as the carriage 21 moves to the left. Subsequently, when the carriage reversal completion signal β is input to the electromagnet drive circuit 52, the attraction force of the electromagnet 41 becomes weaker, and the carriage 21 moves to the left while being smoothly organized. When the carriage is traveling to the left while forming one course in this way, the attraction force of the electromagnet is weakened as described above to prevent it from becoming a load on the carriage. Also, when the carriage 21 is reversed from the left row to the right row at the left end of the knitting width, the control section 51
outputs a carriage reversal start signal α, strengthens the attraction force of the electromagnet 41, and moves the cam plate 25 to the base plate 23.
22 by sliding it to the left relative to the
When the positions of a and 22b are switched and a carriage reversal completion signal β is output from the control section 51, the attraction force of the electromagnet 41 is weakened to smooth the running. Of course, the structure of the knitting machine is not limited to the above structure, but is a knitting machine with a structure in which a carriage runs along a sliding bar made of magnets, and mechanisms such as stitches are switched at both ends of the knitting width. It's good to have. Further, the structure of the electromagnet 41 is not limited to the structure shown in FIG. 4, and the carriage reversal start signal α may be obtained not from the encoder but from position detection means such as a limit switch. As described above, according to the knitting machine according to the present invention, only when reversing the carriage 21, the attraction force of the electromagnet is strengthened and the cam plate 25 is slid to switch the positions of the threads 22a and 22b, so that the carriage knits. While the vehicle is running, the attraction force of the electromagnet 41 is weakened so that the vehicle can run smoothly. Therefore, the energization time is short, which saves energy, and also generates less heat and allows the electromagnet to be made smaller, making it possible to install it in a carriage with limited space. Therefore, it is possible to provide a knitting machine that is compact and consumes less energy.

【 effect 】

As described above, according to the electromagnet according to the present invention, the attraction force is maintained in either the strong or weak state even when the current is turned off by simply energizing it in the opposite direction only at the moment when the attraction force is switched to strong or weak. Therefore, it is possible to provide an electromagnet that consumes very little energy and whose strength can be switched. Since this electromagnet has a small amount of heat generation, it is also possible to obtain the effect that the electromagnet capable of achieving this effect can be made smaller. According to the knitting machine of the present invention, the attraction force of the electromagnet is strengthened only when the carriage is reversed to switch mechanisms such as dowels, and when the carriage is running while knitting, the attraction force of the electromagnet is This makes it possible to run smoothly by weakening the adsorption force, so the adsorption force can be switched from strong to weak in a short period of time, resulting in the effect of reducing energy consumption. Since it consumes less energy and generates less heat, the electromagnet can be made smaller, and it can be installed in the limited space of the knitting machine's carriage, making it possible to provide a compact knitting machine that consumes less energy.

[Brief explanation of drawings]

FIG. 1 is a side cross-sectional view of an embodiment of the electromagnet according to the present invention, FIG. 2 is a timing chart for switching the strength of the electromagnet, and FIG. 3 is a partially cut away state of the carriage of the knitting machine according to the present invention. Fig. 4 is a partially enlarged sectional view of the magnetic attraction member of the carriage, Fig. 5 is a block diagram of the control circuit used in the knitting machine, and Fig. 6 shows the switching of the adsorption force of the knitting machine. FIG. 7 is a timing chart showing a magnetic hysteresis curve of a semi-hard magnetic member. A...First magnetic circuit, B...Second magnetic circuit, 1...Magnet, 2...Semi-hard magnetic member, 3...
Semi-hard magnetic member, 4... Magnetic body to be attracted, 7... Soft magnetic member, 10... Electromagnet drive circuit, 11...
Electromagnet, A'...first magnetic circuit, B'...second magnetic circuit, α...carriage reversal start signal, β...
... Carriage reversal completion signal, 21... Carriage, 25... Cam plate (switching means), 29...
Sliding bar, 28... Magnetic adsorption member, 41... Electromagnet, 42... Magnet, 43... Soft magnetic material member, 44
a...Semi-hard magnetic member, 44b...Semi-hard magnetic member, 45a...Exciting coil, 45b...Exciting coil, 51...Control circuit (means for outputting a carriage reversal start signal and a carriage reversal completion signal) ,
52...Electromagnet drive circuit.

Claims (1)

[Scope of Claims] 1. A first magnetic circuit is constituted by a semi-hard magnetic member having an excitation coil, a magnet, and an attracted magnetic body, and the first magnetic circuit is constituted by the magnet and a soft magnetic member. By configuring a second magnetic circuit different from the circuit, and providing an excitation coil driving means that excites the excitation coil for a short time in the same direction or in the opposite direction to the direction of the magnetic field generated by the magnet, An electromagnet characterized in that the electromagnet is configured to control the attraction force of the attracted magnetic body in a circuit by switching between strong and weak states. 2. In a knitting machine equipped with a switching means for switching knitting mechanisms such as stitches and cams when reversing the traveling direction of the carriage running along a sliding bar made of magnetic material at both ends of the knitting width, an excitation coil is a first magnetic circuit comprising a semi-hard magnetic member, a magnet, and the sliding bar; and a second magnetic circuit different from the first magnetic circuit comprising the magnet and a soft magnetic member. means for outputting a carriage reversal start signal at a reversal position at the end of the knitting width; means for outputting a carriage reversal completion signal at a slightly inner position or at a timing slightly delayed from the carriage reversal start signal, and the excitation coil is caused to move in the same direction as the magnetic field by the magnet for a short time by the carriage reversal start signal. and excitation coil drive means for exciting the excitation coil in a direction opposite to the magnetic field of the magnet for a short time in response to the carriage reversal completion signal, and when reversing the running direction of the carriage at both ends of the knitting width, Only between a carriage reversal start signal and a carriage reversal completion signal, the magnetic flux density of the first magnetic circuit of the electromagnet is increased to strengthen the attraction force between the electromagnet and the sliding bar, and the switching means is activated. A knitting machine characterized by being configured to