JPS62294923A - Oil temperature detector for hydraulic elevator - Google Patents

Abstract

PURPOSE:To enable every temperature in a working range to be detected by one detector by comparatively processing a stored reference temperature and a detection output, judging an oil temperature from the addresses of stored contents and judging an abnormality when a comparison output is not inverted. CONSTITUTION:A level output sequentially read out of built-in memory means by the output address of scanning means 1a is supplied to a comparator 15 via a D/A converter 16 as a reference value. A detection output from an oil temperature sensor 11 is also supplied to the comparator 15 and level detecting means 1b judges an oil temperature level from an address when a comparison output is inverted. On the other hand, when the comparison output is not inverted even though a scanning is terminated, an abnormality in the sensor 11 is judged by abnormality judging means 1c. This construction enables every temperature in a working range to be detected by a simple and small size instrument using one detector.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] This invention relates to an improvement of an oil temperature detection device for a hydraulic elevator.

[Conventional technology]

FIG. 9 is a block diagram showing a conventional oil temperature control device for a hydraulic elevator disclosed in, for example, Japanese Patent Application Laid-Open No. 57-170372.

In the figure, (1) is a cylinder filled with oil (2), (3
) is the plunger inserted into the cylinder (1), (4)
is a cage connected to the head of the plunger (3), (5) is a conduit connected to the cylinder (1), and (B) is a conduit (5).
(7) is the descending solenoid valve that also discharges oil from the pipe (5), and (8) is the ascending solenoid valve. Hydraulic pump connected to (8), (9) a hydraulic pump electric motor that drives the hydraulic pump (8), (10) an oil tank connected to the lowering solenoid valve (7) and the hydraulic pump (8) ,(90),
(91) is an oil temperature detector installed in the oil tank (1G).

In other words, when an ascending command is issued, the electric motor (9) rotates,
In addition to driving the hydraulic pump (8), the lifting solenoid valve (6
) is controlled. Now the oil ('2) in the oil tank (lO) is
) is sent from the lifting solenoid valve (6) to the cylinder (1) through the conduit (5), so the car (4) rises. Also, when a descending command is issued, the descending solenoid valve (7) is controlled, and the oil (2) in the cylinder (1) passes through the pipe (5) and the solenoid valve (7) to the oil tank (10). Since it is discharged, the basket (4) descends.

In a hydraulic elevator, when the temperature of the oil (2) decreases, the viscosity of the oil (2) changes, and the ride comfort of the car (4) worsens and the landing error increases. Therefore, regulations also stipulate that the oil temperature be maintained at a certain value or higher. The oil temperature detectors (90) and (91) detect this.
When the oil temperature is out of the lower limit, the oil temperature detector (90) is activated, the electric motor a (9) is rotated idly, and the oil pressure is transferred to the cylinder (1).
The oil (2) is circulated through the oil tank (10) and appropriate pipes (not shown) without being sent into the oil tank (10).
2) Heat to raise the oil temperature. This operation continues for a certain period of time and then is stopped. 1. Next, when the oil temperature rises and exceeds the upper limit, the oil temperature detector (81) is activated, and the calling circuit is disconnected from the car (4). By stopping the operation, the oil (2) is cooled and the oil temperature is lowered. In this way,
The oil temperature is maintained between the upper and lower limits.

[Problem that the invention seeks to solve]

In conventional oil temperature detection methods, the oil temperature detector can only detect either rising or falling oil temperature fluctuations, so two oil temperature detectors are provided to constantly detect both rising and falling fluctuations. It is necessary to separately detect rising fluctuations and falling fluctuations with each oil temperature detector, and therefore two oil temperature detecting devices must be provided, making the entire device larger and more expensive.

This invention solves the above-mentioned problems, and aims to provide an oil temperature detection device that can detect all oil temperatures within the range of oil temperatures used in hydraulic elevators using a single oil temperature detector.

[Means for solving problems]

The oil temperature detection device for a hydraulic elevator according to the present invention calculates in advance the output voltage information of each sensor for the oil temperature detected by the oil temperature detection sensor and stores the output voltage information for each address in a predetermined voltage level order. Then, input the temperature sensor output to the comparator that is input, and detect the presence or absence of a change in the output logic level output from the comparator. If no change in the logic level is detected, abnormal oil temperature fluctuation or oil temperature sensor failure is detected. The apparatus is equipped with means for determining the oil temperature based on the output voltage information at the time of detection when a change in the logic level is detected.

[Effect]

In a state where the comparator of the oil temperature detection device for a hydraulic elevator in this invention is inputting a constant level of oil temperature detection voltage from the oil temperature sensor, the oil temperature sensor outputs an output from the storage unit via the D/A converter. When the logic output level of the comparator is scanned by sequentially inputting voltage output signals from the maximum possible voltage level to the minimum voltage level by the scanning means, the voltage level read out from the storage section at the time of detection of reversal of the logic output level is The temperature is determined by the level detection means, and when no reversal of the logical output level is detected until the end of the scan, the abnormality determination means determines whether the oil temperature sensor is abnormal or the oil temperature is abnormally fluctuating.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 8. In addition, in Fig. 3, (1) to (10) are the 9th
Shows the same parts as the figure.

FIG. 1 is an overall configuration diagram of an embodiment of an oil temperature detection device for a hydraulic elevator according to the present invention. As is clear from Fig. 1, an oil temperature sensor (11) is provided to detect the temperature of the oil (2) in the oil tank (10), and the temperature detected by the oil temperature sensor (11) is converted into voltage and a comparator is connected. (15) as an input, and the comparator (15) compares the input value with the preset voltage value for each detected oil temperature of the oil temperature sensor from the maximum voltage level to the minimum voltage level. (15)
The logic output level of is scanned by the scanning means (1a) and the presence or absence of inversion of the logic output level during scanning is detected by the level detection means (1b).As a result, the oil temperature is determined from the set voltage level at the time of the logic output level inversion. At the same time, when no level reversal is detected, the abnormality determining means (Ic) determines abnormal fluctuations in oil temperature or failure of the oil temperature sensor. Based on the determination result, the oil temperature control circuit (26) is driven to safely operate the hydraulic elevator.

In the tJIJz diagram, (11) is the oil temperature sensor, for example N
Use a TC thermistor etc. (+) is a DC power supply, (12
) to (14), (17) are resistors, (18) are variable resistors,
(15) is a comparator, (1G) is a D/A converter, Vs is this reference voltage input, DI is an 8-bit digital signal input consisting of oo-o7, and VD is an analog output voltage determined by DI and Vs. It is. (20) is a microcomputer that functions as scanning means, level detection means, and abnormality determination means; (21) and (25) are interface input and output circuits that convert analog signals and digital signals; Receive a signal. (2
3) is a ROM, and (24) is a RAM. (26
) is an oil temperature control circuit, and (27) in the circuit is an oil temperature increase circuit when the oil temperature drops, for example, to rotate the electric motor and recirculate the oil.
Connect a heater. In addition, the oil temperature control circuit (28
) (28) is an operation stop circuit when the oil temperature rises, and for example, stops the car by disabling hall calls and making it impossible to start the car.

FIG. 4 is a temperature-voltage characteristic diagram showing the relationship between the temperature detected by the thermistor (11) and the output voltage. Hydraulic elevators generally operate normally within the range of 5℃ to 60℃, so the temperature can generally be controlled within this range, but errors in detection circuits such as thermistors and low temperatures may occur due to low oil temperature during winter installation. Considering the case, the oil temperature detection range may be controlled within a range of about 1°C to 70°C.

Since the oil temperature detection range is set as above, the voltage VIH that is divided by the resistor R1 and the thermistor resistor Rrs and appears across the thermistor (11) is the thermistor divided voltage when the detected oil is 1 m - 5°C to 70°C. (VTH(-5)) is the thermistor partial voltage (VlH(7o)) when the detected oil temperature is 70℃
The reason why it is larger is because an NTC thermistor is used.

Next, the setting of the analog output of the D/A converter (16) will be explained. If the oil temperature is lower than the above -5℃ or if the thermistor (11) is disconnected, it is necessary to determine this as an abnormality when detecting the oil temperature, and this abnormality judgment starts operation outside of oil temperature control. It is necessary to make sure that it does not become impossible.

Therefore, in order to achieve this, the analog output v [l is the above VI
Lower than H(-5) (e.g. V r+u-s) -0,3
V) Change the value of the resistor (18) to set Vs.

Next, the oil temperature detection operation will be explained with reference to FIGS. 5 to 8. (23) in Fig. 5 is a ROM, such as an EPROM or EEP.
It consists of ROM etc. Here, V
l) The digital input voltage information DI for outputting the /A change detection force VD is stored as an 8-bit binary value of [)O-07 bits, and is stored at address 1000. After that, for example, TM(-5) to TM(7
0) (76 values) are stored in 1°C increments.

Therefore, as mentioned above, TM (-5) = FFH (-!5℃
) will be included. 6 to 8 are oil temperature detection programs, and the initial setting routine shown in FIG. 6 is a program that is executed only when the power is turned on or when the CPU is reset, for example.

When the power is turned on now, the CPU (22) goes through this initialization routine after being reset. This results in flow (5
0), the output from the CPU (22) passes through the output circuit (25) to 0.
UTI, that is, all 8-bit signals of [1G-07 are
FF, which is 1", is input to Dl, and D
/A converter (1B) (7) Output Vo is V yH (-s)
Generates a voltage of -0.3V. At the same time, this output value is RA
(24) on T) is stored as IMO. After this, depending on the interrupt cycle setting in flow (51) (for example, according to the Intel 8085A, to set a cycle interrupt such as RST7.5), after a certain period of time, the flow jumps to the oil temperature processing routine in Figure 7.8. Become.

Assuming that the oil temperature sensor (11) is disconnected, etc.
The oil temperature sensor (11) has an oil temperature of -■, and the (+) input oil temperature sensor voltage VIH of the comparator (15) has a value larger than VTH (-5).

Therefore, since this value is larger than the (-) inputs of the comparator (15), the comparator (15) outputs the (◆) potential and the (+)
) voltage as rFFuJ signal by input circuit (21).
It is input to the PU (22). For this reason, the flow in Figure 7 (52
) is stored in the RAM (24) as THMI=FFn.

Next, by passing through flow (5B) and (57) as a result of flow (53) where VTH is determined to be larger than V T
Enter the THMO value FFH into G. This means that the current oil temperature is recognized as FFH as a data value. Next, THMO (FFH
-1) value, that is, the thermistor voltage information rFE+J stored at address 10018 in the ROM (23), is again input to the DI as the no-01 value through flows (59) and (80), and is input to the D/A converter. is output through. This output voltage is DI=FFH and output Vo-V+h(-5
) -0.3V vs. -c--H = 8 Next, when an interrupt occurs again, processing starts again from flow (52), and in this case too, the oil temperature sensor voltage Vl)l becomes Vllll.
(-5>, so THM I = IFF+,
Since FLAG1=Fh, we will go from (54) to (55). As a result, the oil temperature value is determined to be FFH.

By repeating each flow in this way, it was determined that the oil temperature was outside the normal range, so flow (54)
, (55), and the output and flag are reset at (83). In this example, if it is determined that the oil temperature is outside the range, flow (6)
In step 3), an output is generated to turn off the oil temperature indicator (29), and an abnormality signal is also generated to cause the elevator to be stopped, for example, or rendered inoperable. After the abnormality of the elevator oil temperature detection unit is determined by the oil temperature indicator turning off as described above,
When an interrupt occurs again, the processing in flow (52) is performed again. The detection circuit that replaces the oil temperature sensor etc. mentioned above is composed of a semiconductor such as a thermistor, but thermistor has a large current,
When voltage is used, the resistance change increases due to self-heating of the thermistor, resulting in detection errors. For this reason, it must be driven at a low voltage. However, such a low voltage,
For example, if a low-current thermistor detection signal is sent from the oil tank to the control panel, there is a risk of a surge occurring between the two, and in this case, even though the oil temperature is normal, the comparator (1
When the signal to 5) is input to the microcomputer (20), it may be input as an abnormal oil temperature as described above.

In this program, the same oil temperature determination process is always performed at a constant cycle when the CPU is operating, so that it is not determined that the oil temperature is abnormal due to the accidental mixing of an abnormal signal as described above. As a result, if the above abnormality judgment is not made and a voltage input according to the oil temperature is input, THM I will not go to flow (54) for the first time, so it will go to the processing from flow (53) onwards, and will set the specified oil temperature. When it is determined, the flow (54) is canceled and normal display and operation are performed. Next, a case where the oil temperature is, for example, 6° C. will be explained. Assume that THMO is set to the maximum value through flow (50) or flow (63) *VT
H generates a voltage of VHI (6), and comparison 3 (15) (
7) (-) side D/A output (Vllll(-5)-0,3
V) ty) is larger, so in this case flow (52)
, in (53), T)IN I is "00 days", and
Since FLAGI has been reset, flow (54)
Pass through (58). Here, in order to read the voltage information at the next oil temperature detection value from the ROM (23), OIH is subtracted from the output value THMO from the CPU, and the voltage information in the ROM (23) is output to the converter (11 () - 2). .D/A
Since the output is output from the converter (16), the comparator (15) compares the oil temperature sensor output with the analog voltage value and outputs a logical output.

After this, engraving is performed and the HMI signal is taken in again via the input circuit (21), but with a difference of about 01+, VD
The decrease in output is slight, and the same operation is repeated. T.H.
MO is sequentially subtracted and the value at oil temperature 6℃ is TM (6) or T
When M(6)-01H is reached, the input (-
) side becomes large, so the flow (52) occurs due to an interrupt.
THMI changes from roOuJ to rFFuJ and passes through flows (53) and (513) to flow (57).
) to come.

Through flow (57), the oil temperature data THMO corresponding to the oil temperature value just output is stored in THC:G, and this oil temperature detection device detects the oil temperature in the oil tank by capturing the change in THMI.

At the same time, rFFHJ is placed in FLAGI, OIH is subtracted from THMO again, and the process waits for an interrupt. After that, 0 to ↑H in the same way.
After subtracting 4 times, the interrupt flows as (52)-(53)-(
5B) - (81) becomes "Y", that is, r of THMI
The oil temperature data at the point where the change from ooHJ to rFF++J is captured is memorized, and then the oil temperature data is lowered and output, so if it is normal, THMI will always be rFFHJ, indicating that it has been normal four times. It is determined and the process proceeds to the next subroutine (62).

This is because when the difference between the output voltage of the thermistor oil temperature sensor and the D/A output voltage is almost Ov, the output of the comparator (15) will be a forward or reverse voltage if either is even slightly high. The oil temperature changes from moment to moment, and in some cases the comparator (15) may oscillate.
The positive and reverse voltages may be repeated, and when the input is taken in such a state, the THMI may be ro depending on the timing of the input.
It can occur in both OJ and rFFJ,
THMI once became rFFHJ as unreliable data, but if you input it next time with rooHJ, the flow (53)
-(54)-(133), and start again from the beginning (TH
The reliability is increased by having the MO calculate from rFF++J).

- If the rFFuJ value of THM I continues four times after the force change, the process goes to flow (62), it is determined that the oil temperature detection is reliable, and the oil temperature determination subroutine process is performed. FIG. 8 shows the oil temperature determination routine.

The oil temperature data just detected is stored in the memory as THC:G. On the other hand, after address 1000)1, the ROM (23) in FIG. 9 contains the set oil temperature data value corresponding to the oil temperature value as described above, and in the flow (71),
7B) - (77) and returns to (71) again, the set oil temperature data value is moved to the lower temperature side, and the set oil temperature data value becomes 7)1(7), that is, 7℃. Then, the judgment in flow (71) leads to (73), and (76)
Since FRAG2 is set to rFFHJ in advance, the process goes to the subroutine (74), and the oil temperature, for example "6", is output from the output circuit (25) to the display (29). As a result, the oil temperature detection ends, and the oil temperature detection is repeated again in the same way through the flow (75)-(83).In this case, the oil temperature is low, for example, the lower limit oil temperature ( For example, since the oil temperature is lower than 10° C.), a signal is outputted to the oil temperature raising circuit (27) through the output circuit (25), and an oil temperature raising operation is performed.

Even if the oil temperature is within the normal range and currently on the high side, the same oil temperature detection is performed, the oil temperature is displayed, and a signal is input to the operation suspension circuit (2 days), which prevents the oil temperature from rising by suspending the operation, etc. . In this case, the return to operation is also carried out by similar oil temperature detection and settings in the operation processing subroutine.

Next, a case will be described in which, for example, the oil temperature sensor becomes short-circuited. In this case, VIH is Ov, and the comparator (15
) is Ov. As above, THM
O is subtracted from rFF++J, but since the (-) side of the comparator (15) is at high voltage, T)! M I is rohJ and (52)-(53)-(54)-(5B)-(
Repeat each rope in sequence from 59) to (81).

Here, when the value of T)l)10 becomes r2F++J (for example, a value of 70℃) in this example, the flow (59) passes through (54)-(5) and turns off the oil temperature display in the same way as when the wire is disconnected. When an abnormal signal is generated, for example, the elevator is stopped.

Here, the final value of THMO output is set to 2FH is OOu
When compared by subtracting up to Since it is conceivable that the oil temperature may rise beyond the normal range, the structure is designed to minimize this including the oil temperature detection error.

In this embodiment, the oil temperature data is scanned by subtraction starting from the low temperature side, but the same effect can be obtained by adding the oil temperature data.

Also, one count of oil temperature detection was performed every interrupt cycle using a D/A converter instead of an A/D converter, but
This is because the oil temperature of the hydraulic elevator does not change suddenly, and the response of the thermistor oil temperature sensor is slow because it is not directly immersed in oil, so it can be used without any problems in actual use.

Further, although the set oil temperature data is set in units of 1°C, there is no particular restriction.

Furthermore, although the display in the event of an abnormality is turned off, a disconnection or oil temperature drop abnormality and a short circuit or oil temperature rise abnormality may be distinguished by lighting using a display other than numbers.

〔Effect of the invention〕

As described above, according to the present invention, the voltage output value of the oil temperature detection sensor and the sensor output voltage setting value for each oil temperature in the oil temperature range wider than the normal oil temperature range in which the sensor performs oil temperature detection are determined. A comparator compares the entire oil temperature range, and the oil temperature is detected based on the logic output level reversal detection of the comparator during the comparison, and the oil temperature increase fluctuation or oil temperature detection is performed based on the logic output level non-reversal detection. Since the system is configured to detect fluctuations in decrease, a single oil temperature sensor can perform temperature determination over a wide range, and also detect abnormal oil temperature fluctuations, which has the effect of reducing the overall size and cost of the apparatus.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of an embodiment of an oil temperature detection device for a hydraulic elevator according to the present invention, FIG. 2 is a configuration diagram showing electrical connections of an oil temperature detection circuit of the invention, and FIG. 3 is a configuration diagram of a hydraulic elevator. Figure 4 is a characteristic diagram of the oil temperature detector, Figure 5 (a)
, (b) is a memory configuration diagram of the storage section, FIGS. 6 to 8 are flowcharts showing the oil temperature detector program, and FIG. 9 is a configuration diagram of a conventional hydraulic elevator. In the figure, (1a) is a scanning means. (1b) is a level detection means, and (IC) is an abnormality determination means. (2) is oil, (10) is oil tank, (15) is comparator,
(18) is a D/A converter, and (26) is an oil temperature control circuit. Note that the same reference numerals in Figure 1 indicate the same or equivalent parts.

Claims (3)

[Claims] (1) In a hydraulic elevator oil temperature detection device that detects the oil temperature of a hydraulic elevator with an oil temperature sensor and controls the elevator based on the detected output, each oil in the oil temperature range that can be thermoelectrically converted by the oil temperature sensor A memory section stores each output voltage information corresponding to the temperature at each address in a fixed order, and the voltage information read from the memory section is analogized with a level difference with respect to the voltage value output from the temperature sensor. a D/A converter for converting the oil temperature sensor; and a scanning means for sending the address contents of the storage unit sequentially from the upper address through the D/A converter and scanning the comparator output to a comparator for inputting the oil temperature sensor output; A level detection means detects the presence or absence of a logic level change in the comparator output during scanning, and the oil temperature is determined based on read address information when a logic level change is detected, and when no change is detected, an oil temperature abnormality or oil temperature sensor failure is detected. An oil temperature detection device for a hydraulic elevator, comprising an abnormality determination means for determining an abnormality. (2) A patent claim characterized in that the maximum output voltage level of the D/A converter is set higher than the voltage signal level corresponding to the lowest oil temperature that can be detected by the oil temperature sensor within the normal oil temperature value range. The oil temperature detection device for a hydraulic elevator according to item 1. (3) The minimum output voltage level of the D/A converter is set to be equal to or lower than the voltage signal level corresponding to the highest oil temperature that can be detected by the oil temperature sensor within the normal oil temperature value range. An oil temperature detection device for a hydraulic elevator according to claim 1.