CN101651066B

CN101651066B - Digital type thermal relay

Info

Publication number: CN101651066B
Application number: CN 200910104701
Authority: CN
Inventors: 郭永明
Original assignee: GUO YINLI
Current assignee: GUO YINLI
Priority date: 2009-08-26
Filing date: 2009-08-26
Publication date: 2012-12-26
Anticipated expiration: 2029-08-26
Also published as: CN101651066A

Abstract

The invention relates to a digital type thermal relay for protecting a motor. An alloy movable piece, a guide plate and a lever are sequentially connected in a casing, a push rod and a pointer are installed on the lever, and the length of the pointer is 5 times of a distance from a rotating shaft to the push rod; the lever, the push rod and the pointer rotate by an error caused by the zero drift of the alloy movable piece through the guide plate, a distance between the push rod and a disconnection position of a switch is changed finally, and the change of the distance is amplified by 5 times through a pointer table comprising the pointer and a digital scale. An electrician can judge the magnitude of the error of the thermal relay according to digits displayed by the pointer table and judge whether the thermal relay effectively protects the motor or not. The long-term usage of the thermal relay which has large error and does not act as a protective action is prevented; a current calibration knob can be used for changing the distance between the push rod and the disconnection position of a contact point of the switch and can be used for modifying the error. The protective property of the thermal relay with the modified error meets the standard, and the protected motor can not be burnt out because of overload phase failure.

Description

Digital type thermal relay

Affiliated technical field

The present invention relates to a kind of thermal relay of protecting motor, especially a kind of digital type thermal relay that can show spacing between push rod and the switch contact open position.

Background technology

At present; Known thermal relay is made up of bimetal leaf, guide plate, lever, push rod, switch, current calibration knob, test key etc., and bimetal leaf is crooked when motor overload, and bimetal leaf promotes guide plate; Guide plate promotes lever; Push rod pull switch contact on the lever moves to open position, and switch is broken off, the protection motor.But the thermal relay uses a Jia time, to produce a large error, it can not effectively protect the motor, due to an alternation of high and low temperature, in particular because of an overcurrent, the bimetal temperature to the phase transformation point temperature, the bimetal the movable piece of the alloy to be a phase change, i.e. alloy structure, the crystal arrangement is changed, the line of the alloy moving film swell coefficient generating dramatic changes within the alloy moving film stress (thermal stress, mechanical stress, the residual stress) The size, distribution changes, stress changes the alloy movable piece of elastic modulus, the bent and other physical changes, alloy movable piece produce zero drift, the alloy movable piece can not be restored to the initial state, resulting in the guide plate, the lever position change , eventually putting position changes, putting off position with switch contacts between the Distance change; ordinary putter with thermal relay does not show the distance between the switch contacts open position value and the changes in the value function, there is no error correction capabilities.Can only let the big inoperative thermal relay of error use for a long time like this, cause the motor of thermal relay protection to burn out in a large number.

Summary of the invention

Do not show distance values and changing value function between push rod and the switch contact open position in order to overcome the ordinary hot relay, also do not have the round-off error function, the present invention provides a kind of digital type thermal relay; Can show spacing and changes in spacing value between thermal relay housing inner push-rod and the switch contact open position; Be error, and adjustable this spacing, round-off error; Prevent that the big thermal relay that does not shield of error from using for a long time, reaches the purpose of effective protection motor.

The technical solution adopted for the present invention to solve the technical problems is:

Shouldering of existing thermal relay guide plate control the pointer that direction makes progress is installed on the bar, 5 times of its length are to push rod to shaft length, and pointer upwards pierces into and is positioned at the slot that the digital calibration chi is arranged on the limit of regulating on the panel.Pointer and digital calibration chi constitute pointer gauge.Lever rotates, push rod rotates, pointer rotates because the error that the null offset of alloy moving plate brings makes through guide plate; The error that the null offset of alloy moving plate brings makes finally that spacing changes between push rod and the switch open position; Therefore only need to survey between push rod and the switch open position spacing and change and just surveyed null offset, adjust between push rod and the switch open position spacing and just revise null offset.Because push rod and pointer are at same lever shaft place; There is not relative motion between them; Pointer length is 5 times that push rod rotates half warp, and the arc length that pointer rotates is 5 times that push rod rotates arc length, and push rod forwards the switch open position to from initial position displacement is amplified 5 by pointer gauge and shown and show; The numeral that the pointer gauge pointer shows is exactly a spacing between push rod and the switch open position; Spacing and changing value between unresolvable push rod of naked eyes and the switch open position are amplified 5 by pointer gauge show and show, so digital type thermal relay there are the function of spacing and changing value between enlarged and displayed push rod and the switch open position, the function of display error.

Because of current calibration is rotary with eccentric wheel, spacing between scalable push rod and the switch contact open position is revised the error of the null offset generation of alloy moving plate with it.The numeral that the electrician shows according to pointer gauge can be judged the error size of thermal relay, can the judgement thermal relay effectively be protected motor? Prevent that the thermal relay that error very much not shields from using for a long time.

Of the present invention have following advantage with the ordinary hot relay.

1. the function that shows spacing between push rod and the switch open position is arranged, and according to the numeral that pointer shows, the electrician can judge the error size of thermal relay, can the judgement thermal relay effectively be protected motor?

2. the function that round-off error is arranged: regulate distance values between push rod and the switch contact open position with the current calibration knob; Revise the error of the null offset generation of alloy moving plate; Make the digital type thermal relay error at zone of reasonableness; Prevent that the thermal relay that error very much not shields from using for a long time, can effectively protect motor.

3. the function that fault in enlargement is arranged.

Embodiment:

Fig. 1 is the vertical view of first embodiment of the invention.

Fig. 2 is the A--A cutaway view of Fig. 1.

Fig. 3 is two of embodiment

Fig. 4 is three of embodiment

Among the figure: 1. pointer, 2. lever, 3. push rod, 4. guide plate, 5. switch contact, 6. switch open position, 7. bimetal leaf, 8. slot, 9. current calibration knob, 10. digital calibration chi, 11. regulate panels, 12. test keys, 13. switches, 14. rotating shafts

Fig. 1:, digital calibration chi (10), pointer (1), current calibration knob (9) are arranged regulating on the panel (11); Slot (8), test key (12), switch open position (6).Pointer gauge is made up of pointer (1), digital calibration chi (10), and pointer 0 numeral is the switch de-energized; The numeral that pointer gauge shows is 5, spacing between expression shell inner push-rod and the switch contact open position (after the amplification), expression push rod (3) pull switch contact (5) is to the required displacement of switch open position.The pointer numeral is big more; Expression push rod (3) is big more with pull switch contact (5) spacing; Vice versa. and among Fig. 2: pointer (1) is contained in lever (2) rotating shaft, and still at lever (2) middle part, pointer (1) is upward through the slot (8) that the side of regulating on the panel (11) has digital calibration chi (10) to push rod (3); Digital calibration chi (10) is the convex curved surface, makes the scale numeral evenly.Pointer (1) length is push rod (3) 5 times to rotating shaft (14) length, because lever receives moving plate, guide plate promotes; Rotate; Also with rotating, the arc length that pointer (1) rotates is 5 times that push rod (3) rotates arc length to pointer (1), and push rod (3) rotates arc length by 5 times of pointer (1) amplifications conversely; When push rod (3) pull switch contact (5) to switch open position (dotted line place among the figure), switch (13) breaks off, and is exactly that numeral 5 moves to 0 distance (seeing Fig. 1 pointer numeral) on pointer gauge; Pointer gauge shows that push rod is to distance values and changing value between the switch de-energized.The electrician can judge the error size of thermal relay according to distance values and changing value that pointer gauge shows, can the judgement thermal relay effectively be protected motor? Prevent that the thermal relay that error very much not shields from using for a long time;

Can change spacing, recoverable error between push rod and the switch contact open position with the current calibration knob.The protective feature of the thermal relay of round-off error can satisfy standard, and protected motor can not burn out because of the overload phase failure.

Pointer (1) can be made with elastic wire or insulating material.

Among Fig. 2: pointer (1) is contained on the lever (2), is not contained in lever (2) rotating shaft.

Among Fig. 3: pointer (1) is contained on the push rod (3).

It is thus clear that principal character of the present invention is operating state (distance values between push rod and the switch de-energized), the display error that shows thermal relay with digital quantitative; Utilize current calibration knob round-off error; Make thermal relay be in the state of effective protection motor, prevent that the thermal relay that error very much not shields from using for a long time.

Above-mentioned improvement does not influence former thermal relay mechanical transmission course, can not increase resistance, and is simple.

Claims

1. digital type thermal relay; Constitute by bimetal leaf, guide plate, lever, push rod, switch, current calibration knob and test key; It is characterized in that: pointer (1) is installed on the lever in the thermal relay shell, and pointer (1) is upward through the slot of regulating on the panel (11) (8), and slot (8) side is provided with digital calibration chi (10); Pointer and digital calibration chi constitute pointer gauge, and pointer length is greater than the length of push rod to lever shaft.