JPH0156629B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in linear step motors.

Recently, with the automation and unmanned operation of processing and assembly, conveyance devices using linear step motors are being used instead of conveyance means such as belt conveyors due to the demand for improved stopping position accuracy when conveying workpieces. It is becoming more and more common.

FIG. 1 is a partial perspective view showing the structure of a conventional linear step motor.

Reference numeral 1 denotes a primary side portion having a primary magnetic core 11 made of a ferromagnetic material such as pure iron and a winding portion 12, and lower portions at both ends of each primary magnetic core 11 are connected members made of a non-magnetic material such as brass. 13. 2 is a secondary side portion having a secondary side protrusion 21, and the upper end of the primary magnetic core 11 and the secondary side protrusion 21 are opposed to each other with a required distance apart. For example, while the primary part 1 is fixed, the secondary part 2 is movably disposed, and the primary magnetic core 11 is sequentially excited by the winding part 12 by, for example, known means. moves as shown by the arrow in FIG.

Therefore, when each primary magnetic core 11 is excited by the winding portion 12, the magnetic flux generated from the primary magnetic core 11 is directed in the direction of movement of the secondary portion 2, as shown by the dashed line in FIG. pass at right angles. Even if the primary magnetic cores 11 adjacent to each other in the moving direction of the secondary portion 2 are magnetized to different polarities, each primary magnetic core 1
1 is a connecting member 13 made of a non-magnetic material as described above.
Therefore, the magnetic flux generated from the primary magnetic core 11 does not pass through the moving direction of the secondary portion 2. Therefore, the secondary part 2 is given a driving force for movement only by the magnetic flux passing in a direction perpendicular to the direction of movement of the secondary part 2, as described above. Therefore, the conventional linear step motor has drawbacks such as limited propulsive force for movement of the secondary portion 2 from the primary magnetic core 11.

The present invention was created in view of the above circumstances, and
It is an object of the present invention to provide a linear step motor whose secondary side can increase the propulsion force for movement given by the primary magnetic core.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a linear step motor according to the present invention will be described below with reference to the drawings. FIG. 3 is a partial perspective view schematically showing the configuration of the main parts of the linear step motor according to the present invention, FIG. 4 is an explanatory diagram of the magnetic flux in FIG. 3, and FIG. 5 is an explanatory diagram of the operation of the linear step motor. be.

Reference numeral 3 denotes a secondary side portion provided with a secondary side protrusion 31, and has the same structure as the secondary side portion 2 of the conventional linear step motor described above.

As shown in FIG. 3, the secondary protrusion 31 has a substantially rectangular cross section, has a longitudinal direction perpendicular to the direction of movement of the secondary part 3, and is convex in the direction of movement of the secondary part 3. The protrusions are provided with a predetermined pitch of P (Fig. 5). Reference numeral 4 denotes a primary side portion made of a ferromagnetic material such as pure iron, which includes a base 41 formed in the shape of a parallel plate, and a plurality of primary parts, which will be described later, formed integrally with the base 41 on the upper surface of this base 41. Side magnetic cores A, B, C, and A', B',
It is equipped with C′... The primary side magnetic core A has protrusions 41a ₁ and 4 at its tip, which have a substantially rectangular cross section in plan view and whose longitudinal direction is orthogonal to the direction of movement of the secondary side portion 3.
2a ₂ is provided in a protruding manner opposite to the secondary side protrusion 31. Primary magnetic cores B, C, which are arranged at regular intervals from the primary magnetic core A along the movement direction of the secondary portion 3 and have the same structure as the primary magnetic core A;
D... is arranged. For convenience, the primary magnetic cores A, B, C, . . . are referred to as a front row group. Further, a primary magnetic core A' is provided which is symmetrical to the primary magnetic core A with respect to the moving direction of the secondary portion 3 and has the same structure as the primary magnetic core A. Further, a primary magnetic core A' is provided symmetrically with primary magnetic cores B, C, ... with respect to the moving direction of the secondary portion 3 from the primary magnetic core A', and has the same structure as the primary magnetic core A. , B′, C′... are called the back group.

Here, the protrusion of the primary magnetic core B of the front row group is 42
b ₁ and 42b ₂ , and the same symbols as above are used for the other protrusions on the primary magnetic core.

And the protrusions 42a ₁ , 42a ₂ , 42a ₁ ',
The width of the secondary side portion 3 of 42a ₂ '... with respect to the moving direction is the same width as the protrusion 31. moreover,
The arrangement pitch of the primary magnetic cores A, B, C and A', B', C' is set as follows.
In the illustrated example in FIG. 5a, only eight pieces arranged on the front row side of the primary magnetic core are shown, and illustration of the rear row side is omitted. In FIG. 5a, in a state where the opposing surfaces of the secondary protrusion 31 and the protrusion 42a ₁ of the primary magnetic core A are in agreement with each other, the primary magnetic core B is centered by 1/8 of the pitch P described above. It is located close to A. Next, the primary magnetic core C is the primary magnetic core B.
It is placed closer to the primary magnetic core B by 1P/8 minutes. Hereinafter, in the same manner as above, each primary magnetic core placed on the right side is placed closer to the primary magnetic core on the left side by a pitch of 1P/8 minutes with respect to each primary magnetic core adjacent to the left side. ing. The same applies to the primary magnetic cores A', B', and C' of the rear row group. In addition, each primary magnetic core A, B,
C, and A', B', C'... are provided with a winding portion 43 for excitation. These winding portions 43 are connected so that the primary magnetic cores A and A, B and B, C, C', . . . form electromagnets with the polarities shown, respectively.

In Figure 5a, the polarity of the primary magnetic core A is N.
(S), the polarity of the primary magnetic core A' is N(S), the primary magnetic core C provided one space apart from the primary magnetic core A is S(N), and the polarity of the primary magnetic core C' is N(S). When the winding part 43 is excited so that
, i.e. in the direction of movement of the secondary part 3 . Since the protrusions of the primary magnetic cores A, A' and the facing surfaces of the secondary protrusions 31, 31 are aligned with each other, only an attractive force acts between the two protrusions, and no propulsive force acts. However, in the primary magnetic cores C and C', the protrusions and the secondary protrusions 31 and 31 are shifted by 1P/4, so a driving force to the left acts between the protrusions, and the secondary protrusions Part 3 moves to the left.

Due to the above, the protrusions 42a ₁ , 42a ₂ , 42a ₁ ',
42a ₂ ' and both the convex surfaces of the secondary side convexities 31, 31 are also shifted, and a propulsive force to the right acts in the opposite direction to the moving direction of the secondary side portion 3. And the position where the propulsive forces of the primary magnetic cores A, A' and C, C' are balanced,
That is, the secondary part 3 moves to the left by 1P/8 and stops (Fig. 5b).

Stop the excitation of primary magnetic cores A, A' and C, C',
Primary magnetic core B is N (S), primary magnetic core B' is S
(N), primary magnetic core D is S(N), primary magnetic core
When the winding part 43 is excited so that D' becomes N(S), the secondary part 3 moves further to the left by 1P/8 from the above-mentioned position and stops (Fig. 5). c).

Stop the excitation of the primary magnetic cores B, B' and D, D',
The primary magnetic cores C, C' and E, E' are excited in the same manner as described above. As a result, the secondary part 3 moves further to the left by 1P/8 from the position of and stops (Fig. 5d).

Similarly, as shown in e to h, by selectively exciting every other primary magnetic core in the direction of movement of the secondary part, the secondary part is moved to the left by 1P/8. move towards

In each of the above steps a to h, the primary magnetic cores A, A', C, C', B, B'...
As in the case of the primary magnetic core 11 of the conventional linear step motor described above, the magnetic flux generated by being excited by (see Figure 2).

Therefore, the secondary portion 3 is given a propulsive force by the magnetic flux passing in the width direction of the base 41, and is also given a propulsive force by the magnetic flux passing in the longitudinal direction of the base 41 as described above. The primary magnetic cores A, A', C' and C', B are
, B'D and D', the magnetic flux generated from the primary magnetic cores A and A', C and C', B and B', and D and D' increases.
In this way, since the magnetic flux generated from the primary magnetic core increases, the propulsive force of the secondary section 3 becomes larger than that of the secondary section 2 of the conventional linear step motor described above.

As is clear from the description of the embodiments above, the linear step motor according to the present invention can increase the propulsive force given by the primary magnetic core to the secondary side.

[Brief explanation of drawings]

FIG. 1 is a partial perspective view showing the configuration of a conventional linear step motor, FIG. 2 is a partial explanatory diagram of its operation, FIG. 3 is a partial perspective view showing the configuration of the linear step motor according to the present invention, and FIG. 5 is an explanatory diagram showing the path of magnetic flux, and FIG. 5 is an explanatory diagram of the operation of the linear step motor. 3...Secondary side part, 31...Secondary side convexity, 4...
...Primary side part, 43...Winding part.

Claims (1)

[Claims] 1. A primary magnetic core A that is formed integrally with the base and has a protrusion at its tip and has a winding portion, and a primary magnetic core A that is arranged at a constant distance from the primary magnetic core A along the movement direction of the secondary portion. A front row group consisting of primary magnetic cores B, C, D, etc. having the same structure as the primary magnetic core A, and a front group consisting of primary magnetic cores B, C, D, etc., which have the same structure as the primary magnetic core A, and a front group that is symmetrical to the primary magnetic core A with respect to the moving direction of the secondary side part and is the same as the primary magnetic core A. a primary magnetic core B having the same structure as the primary magnetic core A', which is arranged at the same fixed interval as above from the primary magnetic core A' along the movement direction of the secondary portion; ′, C′, D′..., and a secondary portion having a secondary protrusion facing away from the primary portion and moving on the primary portion. and the polarity of the primary magnetic cores A and C' is N (S),
Also, so that the polarity of primary magnetic cores A' and C becomes S (N), then the polarity of primary magnetic cores B and D' becomes N (S).
In addition, by selectively energizing every other primary winding of the front and rear groups so that the polarities of the primary cores B' and D become S(N),
A linear step motor characterized in that the magnetic flux generated from the primary magnetic core passes in two directions, one parallel to and perpendicular to the direction of movement of the secondary part.