JPH0861455A - Electric motor-driven device - Google Patents

Abstract

PURPOSE: To allow smooth gear change by interlocking with speed change operation, while preventing any runaway, in an electric motor-driven device provided with a mechanical type continuously variable transmission. CONSTITUTION: A control means 16 is provided for controlling a speed change means 8 for shifting a mechanical type continuously variable transmission 2 based on a speed change upper limit value VA set by a speed change operational means 14 and both detected output VF, IF of a speed detection means 10 and a load detection means 12, Regardless of either one of positive load and negative load, rotational speed of the output shaft of the mechanical type continuously variable transmission 2 may not exceed a preset speed change upper limit value VA so as to prevent any runaway and on the other hand, smooth speed change can be achieved in such a way that the rotational speed of the output shaft is continuously decreased from the speed change upper limit value VA so as to increase the output torque little by little in response to the variation of the load when the load becomes large in a positive load condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric device having a mechanical continuously variable transmission such as an electric trolley and an electric conveyor.

[0002]

2. Description of the Related Art Generally, some electric devices such as an electric trolley are provided with a mechanical continuously variable transmission, and speed control is performed by a shift operation of the mechanical continuously variable transmission.

There are various types of mechanical continuously variable transmissions used in such electric devices.
The one disclosed in Japanese Patent Publication No. 57-13221 has a configuration as shown in FIG.

This mechanical continuously variable transmission has an input disc b integrally connected to an input shaft a, a plurality of planetary cones c which rotate in contact with an annular transmission surface of the input disc b, and these. A cone retainer d that rotatably holds the planet cone c, a speed change ring e that is inscribed in the conical surface of the planet cone c, and a planet cone
An output disc g that rotates in contact with the back surface of c and an output shaft i that is interlocked with this output disc g via a pressure adjusting cam h are provided.

An electric motor such as a DC motor (not shown) is connected to the input shaft a, and a load such as a drive gear is connected to the output shaft i. Further, the shift ring e is configured such that its axial position is forcibly displaced by a pilot motor (not shown), and when the shift ring e is at the position of the cone top of the planet cone c, the gear ratio is small. , The output shaft i rotates at high speed, and conversely, the speed change ring c
When it moves to the bottom of the cone, the gear ratio increases and the output shaft i rotates at a low speed.

Here, in the above-mentioned mechanical continuously variable transmission, a rotational speed (hereinafter referred to as output rotational speed) N of the output shaft i and a torque (hereinafter referred to as output torque) T generated on the output shaft i are In general, there is an inverse proportional correlation as shown in FIG. 5, and when the output speed N increases, the output torque T decreases, and when the output speed N decreases, the output torque T increases. Shows the tendency to

Moreover, such inversely proportional output rotational speed / torque characteristics also change depending on the magnitude of the load applied to the electric motor (hereinafter referred to as electric motor torque t).

That is, even when the output speed N is the same,
The output torque T increases as the electric motor torque t increases, and conversely, the output torque T decreases as the electric motor torque t decreases. Therefore, by changing the motor torque t, it is possible to arbitrarily select the output speed / torque characteristic as shown by the curves s ₁ , s ₂ , s ₃ , ... In FIG. The curve indicated by s _T in FIG. 5 shows the output rotation speed / torque characteristic when the input shaft a of the mechanical continuously variable transmission is rotated under the rated value of the electric motor.

Here, the output speed of the mechanical continuously variable transmission /
As a torque characteristic, for example, to obtain the relationship shown by a certain curve s ₁ , the input current value of the electric motor is set corresponding to this curve s ₁ , and the input shaft driven by the electric motor is set.
Keep the rotation speed of a (hereinafter referred to as the input rotation speed) Q constant,
According to the magnitude of the load applied to the output shaft i, the speed change ring e is displaced so that the output rotation speed N corresponds to this. As a result, the shift according to the magnitude of the load is automatically performed along the curve s ₁ .

By the way, in order to cause the mechanical continuously variable transmission to perform the shifting operation under the output speed / torque characteristic as shown in FIG. 5, as described above, the input current value of the electric motor is kept constant.
(Therefore, the output rotation speed N is changed according to the size of the load with the input rotation speed Q kept constant). In that case, when the load applied to the output shaft i becomes smaller, the output is changed accordingly. Since the rotation speed N is increased, the output rotation speed N becomes extremely large and there is a risk that the electric device will run away if there is no pawl.

In order to avoid this, a manually operated gear shift operating portion is provided, and in conjunction with the operation of the gear shift operating portion, as shown in FIG.
As shown in, the upper limit value of the output speed N is N ₁ , N ₂ ,
It is possible to make it variable such as N ₃ , N ₄ , and so on.

That is, when the upper limit value of the output rotation speed is set to N ₁ by the gear shift operation unit, for example,
The torque control for keeping the input current value of the electric motor constant is not performed, and only the position of the transmission ring e is changed so that the output speed N of the mechanical continuously variable transmission does not exceed the upper limit value N ₁ . Then, even if the load becomes smaller than the output torque T ₁ corresponding to the upper limit value N ₁ , the output speed N is held at the upper limit value N ₁ , so runaway is avoided.

On the other hand, when the upper limit value of the output rotation speed N is changed from N ₁ to N ₂ by the operation of the shift operation portion, the electric device is accelerated accordingly.

In this way, the runaway of the electric device can be prevented, and the operation of the speed change operation unit and the speed change of the mechanical continuously variable transmission are interlocked with each other, so that an integrated acceleration feeling can be obtained.

Further, as shown in FIG. 7, the upper limit value of the output rotation speed N is set to N ₁ , N ₂ , N in association with the operation of the gear shift operation unit.
It is also considered that the output current / torque characteristic can be changed by making the input current value of the electric motor variable in association with the variable, such as ₃ , N ₄ , ...

With this configuration, the output rotation speed / torque characteristic is changed according to the operation of the shift operation portion, so that the power at the time of driving the electric device changes, and the output rotation speed is changed by the shift operation. Since it does not exceed the value set according to
There is an advantage that runaway can be prevented.

[0017]

However, the conventional examples shown in FIGS. 6 and 7 have the following problems. That is, the upper limit value of the output speed N in the output speed / torque characteristic of the mechanical continuously variable transmission is N ₁ , N ₂ , N ₃ , N ₄ , ... Since it is limited, the characteristic curve becomes a polygonal line at each point of T ₁ , T ₂ , T ₃ , ... Therefore, smooth gear shift according to the operation of the gear shift operation unit cannot be performed.

For example, it is assumed that the upper limit value of the output rotation speed N is set to, for example, N ₃ by the gear shift operation unit in an electric trolley or the like, and the vehicle is traveling on a flat ground at a constant speed under this rotation speed N ₃ . At this time, torque control is not performed, and only speed control such that the output rotation speed becomes N ₃ .

Then, when the vehicle approaches a slope or the like and the output torque increases more than T ₃ on the way, the speed control is shifted to the torque control, and the output speed N is N along the inversely proportional curve.
_It suddenly drops from the position of ₃ , which causes a sudden drop in running speed.

In addition, in an electric trolley or the like, there are cases where it is desired to get over a step, but in that case, for safety, a low speed and a large power enough to get over the step are required.

However, in the prior art, since the input shaft a of the mechanical continuously variable transmission can be rotated only below the rated value of the electric motor, an output torque above the rated value can be obtained especially in the low speed range. Is not possible, and as a result, there is an inconvenience that it is not possible to overcome a step or the like.

The present invention has been made in order to solve the above-mentioned problems, and enables smooth gear shifting in conjunction with gear shifting operation while preventing runaway, and especially when the vehicle is operating at low speed, The challenge is to be able to generate a large torque.

[0023]

The present invention adopts the following constitution in order to solve the above problems.

That is, the electric device according to the first aspect of the present invention is a gear changing means for changing the rotational speeds of the electric motor for driving the input shaft of the mechanical continuously variable transmission and the output shaft of the mechanical continuously variable transmission. A speed detecting means for detecting the rotational speed of the output shaft of the mechanical continuously variable transmission, and a load detecting means for detecting the positive / negative of the load applied to the output shaft of the mechanical continuously variable transmission and the magnitude of the load applied to the electric motor. And a gear shift operation means for setting a gear shift upper limit value of the rotation speed of the output shaft of the mechanical continuously variable transmission, a gear shift upper limit value set by the gear shift operation means, and detection of both the speed detection means and the load detection means. A control means for controlling the speed changing means on the basis of an output, wherein the control means controls the speed changing means in a positive load state, and a positive load side control section,
And a reverse load side control section for controlling the speed change means in the reverse load state, and the positive load side control section sets the detection output of the speed detection means by the speed change operation means as the detection output of the load detection means increases. The reverse load side control unit includes a deceleration unit that controls the transmission unit so that the transmission unit gradually decreases from the set gear shift upper limit value. The shift means is controlled so as to match the upper limit value.

An electric device according to claim 2 of the present invention comprises:
When the detection output of the load detection means exceeds the rated value of the electric motor, the positive load side control section determines that the detection output of the load detection means decreases the rated value in accordance with the decrease of the detection output of the speed detection means. It includes an overload permitting means for controlling the shifting means so as to gradually increase as a reference.

In the structure of claims 1 and 2, the load detecting means may be a current detecting means for detecting a current supplied to the electric motor or a slip ratio detecting means for detecting a slip ratio of the electric motor. Further, instead of the speed detecting means, a gear ratio detecting means for detecting the gear ratio of the mechanical continuously variable transmission can be used.

[0027]

In the electric device having the structure according to the first aspect, the deceleration means of the positive load side control section shifts the detection output of the speed detection means as the detection output of the load detection means increases in the positive load state. The shifting means is controlled so that the shifting upper limit value set by the operating means is gradually decreased.

That is, even if the load is reduced, the rotational speed of the output shaft does not exceed the upper limit value for gear shifting, while if the load is larger, the rotational speed of the output shaft is correspondingly higher than the upper limit value for gear shifting. The torque is reduced and the torque is gradually increased. Therefore, smooth gear shifting is performed.

On the other hand, the reverse load side control unit controls the speed changing means so that the detection output of the speed detecting means matches the shift upper limit value set by the speed changing operation means in the reverse load state. Moreover, the device is prevented from running away without permission.

Further, in the electric device having the structure according to the second aspect, when the overload permitting means of the positive load side control unit has the detection output of the load detecting means exceeding the rated value of the electric motor in the positive load state. In the above, the speed changing means is controlled so that the detection output of the load detecting means gradually increases with the rated value as a reference in response to the decrease of the detection output of the speed detecting means. That is, even when the load becomes large and the detection output of the load detecting means exceeds the rated value of the electric motor, the rotation speed of the output shaft is reduced and a large torque can be generated.

[0031]

1 is a block diagram of an electric device according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes the entire electric device, 2 denotes a mechanical continuously variable transmission having the structure shown in FIG. 4, and 4 denotes an input shaft of the mechanical continuously variable transmission 2. An electric motor, a DC motor is used in this example, but an AC
It is also possible to apply a motor.

Reference numeral 8 is a speed change means for changing the rotational speed of the mechanical continuously variable transmission 2, and this speed change means is a pilot motor for displacing the speed change ring of the mechanical continuously variable transmission 2 in this example. It is composed of a drive circuit (both not shown) for driving this pilot motor.

Reference numeral 10 is a speed detecting means for detecting the rotational speed of the output shaft of the mechanical continuously variable transmission 2. In the present example, a magnetic sensor for outputting a frequency signal corresponding to the rotational speed, and a magnetic sensor of this magnetic sensor. An F / V converter (both not shown) for converting a frequency signal into a signal having a voltage level corresponding thereto is included.

Numeral 12 is a load detecting means for detecting the positive / negative of the load applied to the output shaft of the mechanical continuously variable transmission 2 and the magnitude of the load applied to the electric motor.
It is composed of a current detector that detects the current supplied to the electric motor 4.

Reference numeral 14 denotes a gear shift operation means for setting a gear shift upper limit value V _A of the rotational speed of the output shaft of the mechanical continuously variable transmission 2, which corresponds to, for example, an operation amount of a gear shift lever (not shown). _A signal of the shift upper limit value V _A of the magnitude that is set is output.

Reference numeral 16 denotes a gear shift upper limit value V _A set by the gear shift operation means 14, and the speed detection means 10 and the current detector 1
2 is a control means for controlling the speed changing means 8 on the basis of both detection outputs V _F and I _F.

The control means 16 is composed of, for example, a microcomputer, and has a positive load side control section 18 for performing shift control in a positive load state and a reverse load side control section for performing shift control in a reverse load state. 20, and shift operation means 14
The shift control means 22 for limiting the shift operation by

The positive load side control section 18 includes a speed reducing means 18a and an overload allowing means 18b.

Here, the input current of the electric motor 4 is the rated value I _T.
Even if it exceeds, if the energization period is within a short time,
The electric motor 4 is less likely to be burnt or the like, and in particular, if the input current to the electric motor 4 tends to increase as the electric device 1 becomes slower, it is possible to temporarily increase the torque. It is convenient to be able to respond to.

Therefore, the maximum value I _MAX of the input current that can be allowed to prevent the motor 4 from burning or the like can be given by the following equation with the preset rated value I _T of the motor 4 as a reference.

The _{I MAX = I T + k 1} · (V MAX -V F) to (although, k ₁ is a proportional constant) (1) where, V _MAX is the maximum value of the variable speed output speed by shift operation means 14 The maximum shift value preset as
V _F is a detection output of the speed detecting means 10.

The deceleration means 18a, in the positive load state,
If the detection output I _F of the current detector 12 is less than the maximum value I _MAX given by equation (1) (I _F <I _MAX), the detection output I _F of the current detector 12 when the load gradually increases The transmission means 8 is controlled so that the detected output V _F of the speed detection means 10 linearly decreases from the shift upper limit value V _A set by the shift operation means 14 as the speed increases.

[0044] That is, the reduction means 18a, the detection output I _F is less than the maximum value I _MAX of the current detector 12 (I _F <I _MAX)
In this case, when the detection output I _F of the current detector 12 changes, the detection output V _F of the speed detecting means 10 is V _F = V _A −k ₂ · I _F (where k ₂ is a proportional constant) ) By controlling the speed changing means 8 so as to satisfy the relationship of (2),
Torque control is executed.

The overload permissible means 18b, in the positive load state, the detection output _{I F} of the current detector 12, the above-mentioned (1)
When the limit value I _LIMIT given by the formula is exceeded (I _F ≧ I _MAX )
, As the detection output I _F matches the maximum value I _MAX, i.e., so as to satisfy the relationship _{I F = I MAX (3)} , controls the shifting means 8.

From the relationship of the equations (1) and (3), I _F = _IT + k ₁ · (V _MAX −V _F ) (4) Therefore, the overload permitting means 18b detects the detection output of the current detector 12. When I _F exceeds the maximum value I _MAX , the detection output I _F of the current detector 12 is proportional to the rated value I _T as the detection output V _F of the speed detection unit 10 decreases. It can be said that the speed changing means 8 is controlled so as to increase substantially.

On the other hand, in the reverse load state, the reverse load side control section 20 makes the detection output V _F of the speed detecting means 10 match the shift upper limit value V _A set by the shift operating means 14, that is, V _The shifting means 8 is controlled so as to satisfy the relationship of _F = _VA (5).

When the gear shift upper limit value V _A set by the gear shift operating means 14 exceeds a predetermined gear shift maximum value V _MAX (V _A > V _MAX ), the gear shift regulating means 22 shifts the gear shift upper limit value V. _A
The upper limit value _VA of the gear shift is limited so that is equal to or less than the maximum gear shift value _VMAX . That is, the shift upper limit value V _A is limited so that the relationship of V _A ≤V _MAX (6) is satisfied.

If the gear shift upper limit value V _A set by the gear shift operation means 14 is less than or equal to the gear shift maximum value V _MAX , the gear shift regulation means 2
The number 2 can be omitted.

Next, the shift control operation of the electric apparatus 1 having the above-described structure will be described with reference to the flow chart shown in FIG. 2 and the output speed / torque characteristic diagram of the mechanical continuously variable transmission 4 shown in FIG. .

After the electric motor 4 is started, the gear shift operation means 1
When a gear shift lever (not shown) 4 is operated, the gear shift operation means 14 causes the gear shift upper limit value V of a magnitude corresponding to the amount of manipulation.
The signal _A is output, and the data of the gear shift upper limit value V _A is taken into the control means 16 (step 1).

Since the mechanical continuously variable transmission 2 is also operated by starting the electric motor 4, the speed detecting means 10 and the current detector 12 output detection signals V _F and I _F , respectively. Then, both detection signals V _F and I _F are similarly fetched by the control means 16 (steps 2 and 3).

The control means 16 carries out the following control on the basis of the data of the gear shift upper limit value V _A , the detection signals V _F and I _F.

First, it is determined whether the gear shift upper limit value V _A set by the gear shift operating means 14 is less than or equal to a predetermined gear shift maximum value V _MAX (step 4).

When the gear shift upper limit value V _A exceeds the gear shift maximum value V _MAX (V _A > V _MAX ), the gear shift regulating means 22
As speed upper limit V _A falls below speed maximum value V _MAX, i.e., so as to satisfy the relationship of the aforementioned equation (6), limits the speed upper limit value V _A (Step 5).

Therefore, even if the gear shift operating means 14 further increases the gear shift upper limit value V _A to accelerate the electric device 1, the gear shift regulating means 22 causes the mechanical continuously variable transmission 2 to move.
The output speed N of the output shaft is limited to the maximum speed N _MAX corresponding to the shift maximum value V _MAX .

On the other hand, in step 4, the shift upper limit value V _A set by the shift operating means 14 is less than or equal to the shift maximum value V _MAX.
When it is determined that (V _A ≦ V _MAX ), the control means 16
Depending smaller or not than the input current value for determining the output speed / torque detection output I _F of the current detector 12 is preset, join the output shaft of the mechanical continuously variable transmission 2 positive load or reverse load It is determined (step 6).

[0058] That is, in the case of a positive load, the detection output I _F of the electric motor 4 is greater than the input current value for determining the output speed / torque set in advance, in the case of reverse load is an electric motor 4 Since the electric power consumption is suppressed and the electric motor 4 is in the power generation state, the electric current becomes smaller than the input current value.

When it is judged that the load is the reverse load, the reverse load side control unit 20 ignores the detection output I _F from the current detector 12, and based on the detection output V _F of the speed detecting means 10, this detection output The speed changing means 8 is controlled so that V _F coincides with the speed change upper limit value V _A set by the speed changing operation means 14, that is, the relationship of the above equation (5) is satisfied (step 7).

Therefore, the gear shift upper limit value V _A set by the gear shift operating means 14 is set as the rotation speed of the output shaft of the mechanical continuously variable transmission 2 among N ₁ , N ₂ , N ₃ , N _MAX . If it corresponds to one, the rotation speeds N ₁ , N ₂ , N ₃ and N _MAX are maintained. That is, in FIG. 3, when the output rotational speed determined by the speed upper limit V _A is N ₁ along the straight line indicated by a symbol a _1, when the N ₂ along the straight line indicated by a symbol a _2, a N ₃ The output rotational speed / torque characteristic changes along the straight line indicated by the reference character a ₃ sometimes and further along the straight line indicated by the reference mark a _MAX when N _MAX .

On the other hand, when it is determined in step 6 that the load is positive, the maximum value I _MAX of the input current is further calculated based on the equation (1) (step 8), and the current detector 12 detection output I _F determines whether less than the maximum value I _MAX of the input current (step 9).

[0062] Then, when the detection output I _F of the current detector 12 is determined to be less than _{I MAX (I F <I MAX} ) is
The deceleration means 18a uses the current detector 1 based on both detection outputs V _F and I _F from the speed detection means 10 and the current detector 12.
As the detected output I _{F of} 2 increases, the detected output V _F of the speed detecting means 10 gradually decreases linearly from the shift upper limit value V _A , that is, the relation of the above-mentioned expression (2) is satisfied. First, the transmission means 8 is controlled (step 10).

Therefore, the gear shift upper limit value V _A set by the gear shift operating means 14 is set as the rotation speed of the output shaft of the mechanical continuously variable transmission 2, for example, among N ₁ , N ₂ , N ₃ , N _MAX . If it corresponds to one, the rotational speed N of the output shaft gradually decreases from one of N ₁ , N ₂ , N ₃ and N _MAX as the load increases. That is, in FIG. 3, when the output rotation speed determined by the gear shift upper limit value V _A is N ₁ , it follows the straight line indicated by reference sign b ₁ and when it is N ₂ , it follows the straight line indicated by reference sign b ₂ of N ₃ . The output rotational speed / torque characteristic changes along the straight line indicated by the reference sign b ₃ at times, and along the straight line indicated by the reference sign b _MAX at the time of N _MAX .

On the other hand, in step 9, the current detector 1
When it is determined that the detection output I _F of No. 2 is greater than or equal to the maximum value I _MAX (I _F ≧ I _MAX ), the overload acceptance unit 18b detects both the detection outputs from the speed detection unit 10 and the current detector 12. V
Based on _{F 1} and I _F , as the detection output V _F of the speed detecting unit 10 decreases, the detection output I _F of the current detecting unit 12 gradually increases linearly from the rated value I _T , that is, as described above. The shifting means 8 is controlled so as to satisfy the relationship of the expression (3) (step 11).

It can be said that, from a different viewpoint, the following control is performed.

Now, the above equation (4) is applied to the speed detecting means 10
By modifying the equation expressed as the detection output _{V F, V F = V MAX} - a _{(1 / k 1) · (} I F -I T) (7).

Therefore, from the relation of the equation (7), regardless of the shift upper limit value V _A set by the shift operating means 14,
As the detection output I _F of the current detector 12 increases as the load increases, the detection output V _F of the speed detecting unit 10 gradually decreases from the shift maximum value V _MAX , that is, with reference sign c in FIG. The output speed / torque characteristic is changed along the straight line shown.

For this reason, particularly on the low speed side, a large torque can be generated exceeding the rated value, and when applied to an electric trolley or the like, a step or the like can be overcome.

It should be noted that, as in this example, the overload permitting means 18b
Providing a is preferable because the advantage of temporarily generating a large torque is exceeded the rated value of the motor 4, is omitted overload permissible means 18b, the detection output I _F of the current detector 12 is the nominal value It is also possible to perform control that does not exceed the limit.

In this case, in FIG. 3, the deceleration means 1
8a controls the speed changing means 8 so as to satisfy the relationship of the above equation (2) with an increase in the load, and, for example, reference numeral b ₁ ,
b _2, b _3, after b _MAX one straight line along output speed / torque is changed, when it reaches a position intersecting the curve d shown by a chain line in FIG. 3, when the load further increases, the one point The output speed / torque changes along the chain line curve d.

In the above embodiment, the load detector 12 is composed of a current detector, but a slip detector for detecting the slip ratio of the electric motor 4 by providing a rotation detector such as a magnetic sensor on the output shaft of the electric motor 4 is used. It can also be configured by means.

When the electric motor 4 has a small capacity, the load can be easily detected by providing a current detector such as a resistor. However, it is difficult to apply it to a large capacity motor. Instead, the load can be detected by the slip ratio detecting means.

In the above embodiment, the speed detecting means 1
0 is provided, but instead of this, a mechanical continuously variable transmission 2
It is also possible to use a gear ratio detecting means for detecting the gear ratio of. The gear ratio detecting means can be realized by detecting the position of the speed change ring of the mechanical continuously variable transmission 2, for example.

Detecting this gear ratio has the following advantages over the case of directly detecting the speed.

Even if the gear ratio of the mechanical continuously variable transmission 2 is constant, the output speed of the mechanical continuously variable transmission 2 changes depending on the characteristics of the electric motor 4. Therefore, when the speed is directly detected,
Although the output speed / torque characteristic of FIG. 3 changes, when the gear ratio is detected, the output speed / torque characteristic of FIG. 3 does not depend on the characteristics of the electric motor 4.

Although k ₁ in the equations (1), (4), and (7) is a proportional constant, the mechanical continuously variable transmission 2 has a proportional constant as indicated by a curve c ′ shown by a broken line in FIG. If k ₁ is changed based on the detection output of the speed detecting means 10 so that the torque becomes larger than the curve d only at the time of almost low speed rotation, the range exceeding the rated value of the electric motor 4 is narrowed. You can

In the equation (2), k ₂ is also a constant of proportionality, but the points e ₁ , e ₂ , e ₃ , e _MAX in FIG. 3 and f ₂ ,
f _3, so that the output rotational speed / torque characteristic at each point of f _MAX is not broken, be changed to k ₂ based on the detection output of the load detecting means 12, it is possible to perform smoother shifting.

[0078]

According to the present invention, the following effects can be obtained.

(1) In the electric device according to claim 1,
In the positive load state, the output shaft rotation speed does not exceed the preset upper limit of shifting even if the load decreases, while the load increases, the output shaft rotation speed correspondingly increases when the load increases. The value is decreased below the value and the torque is gradually increased. That is, since the torque control is continuously executed, smooth gear shifting is performed. Moreover, even in the reverse load state, the preset gear shift upper limit value is not exceeded, so that the device is prevented from running freely.

(2) In the electric device having the structure according to the second aspect, within a permissible range such that the motor does not burn or the like even when the load increases in the positive load state and exceeds the rated value of the motor. Since torque control is performed by, a large torque can be generated.

(3) In the electric device according to claim 3,
When a small-capacity motor is used as the electric motor, the magnitude of the load can be detected with a simple circuit configuration.

(4) In the electric device according to claim 4,
When a large-capacity motor is used as the electric motor, the load size can be detected with a simple circuit configuration.

(5) In the electric device according to claim 5,
The output speed / torque characteristic of the mechanical continuously variable transmission is not influenced by the characteristic of the electric motor.

[Brief description of drawings]

FIG. 1 is a block diagram of an electric device according to an embodiment of the present invention.

FIG. 2 is a flowchart for explaining an operation of gear shift control of the electric device of FIG.

FIG. 3 is an explanatory diagram showing an output rotational speed / torque characteristic of a mechanical continuously variable transmission in the shift control of the electric device according to the present invention.

FIG. 4 is a configuration diagram of a mechanical continuously variable transmission applied to an electric device.

5 is an explanatory diagram showing output speed / torque characteristics of the mechanical continuously variable transmission of FIG.

FIG. 6 is an explanatory diagram of an output rotation speed / torque characteristic of a mechanical continuously variable transmission according to shift control in a conventional electric device.

FIG. 7 is an explanatory diagram of output speed / torque characteristics of a mechanical continuously variable transmission according to another shift control in the conventional electric device.

[Explanation of symbols]

1 ... Electric device, 2 ... Mechanical continuously variable transmission, 4 ... Electric motor, 8
... speed change means, 10 ... speed detection means, 12 ... load detection means
(Current detector), 14 ... shift operation means, 16 ... control means,
18 ... Positive load side control section, 18a ... Deceleration means, 18b ... Overload allowance means, 20 ... Reverse load side control section, 22 ... Shift control means.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area F16H 59:68

Claims (5)

[Claims] 1. A motor for driving an input shaft of a mechanical continuously variable transmission, a speed changer for changing the rotational speed of an output shaft of the mechanical continuously variable transmission, and a rotation of an output shaft of the mechanical continuously variable transmission. Speed detecting means for detecting the speed, load detecting means for detecting the positive / negative of the load applied to the output shaft of the mechanical continuously variable transmission and the magnitude of the load applied to the electric motor, and rotation of the output shaft of the mechanical continuously variable transmission. A speed change operation means for setting a speed change upper limit value, and a control means for controlling the speed change means based on the speed change upper limit value set by the speed change operation means and both detection outputs of the speed detecting means and the load detecting means. The control means includes a positive load side control section that controls the speed changing means in a positive load state, and a reverse load side control section that controls the speed changing means in a reverse load state, and the positive load side control section is The detection output of the load detection means becomes large In accordance with the above, the reverse load side control section includes the speed reducing means for controlling the speed changing means so that the detection output of the speed detecting means becomes gradually smaller than the shift upper limit value set by the speed changing operating means. An electric device, characterized in that the shift means is controlled so that the detection output of the detecting means matches the shift upper limit value set by the shift operating means. 2. The positive load-side control unit controls the load detection means in response to a decrease in the detection output of the speed detection means when the detection output of the load detection means exceeds the rated value of the electric motor. 2. The electric device according to claim 1, further comprising an overload permitting means for controlling the shifting means so that the detection output gradually increases with reference to the rated value. 3. The electric device according to claim 1, wherein the load detection unit is a current detection unit that detects a current supplied to the electric motor. 4. The electric device according to claim 1, wherein the load detection unit is a slip ratio detection unit that detects a slip ratio of the electric motor. 5. The electric device according to claim 1, wherein instead of the speed detecting means, a gear ratio detecting means for detecting a gear ratio of the mechanical continuously variable transmission is used. .